As a Software Engineer at Prime Therapeutics, you are integral to the development and enhancement of innovative healthcare solutions that improve the lives of members and clients. Your role focuses not only on writing code but also on collaborating with cross-functional teams to create systems that support pharmacy benefits management and enhance patient care. This position is vital within a complex healthcare landscape, allowing you to impact the design and functionality of applications that serve millions. You will work on diverse projects, from developing user-friendly interfaces for healthcare providers to optimizing backend systems that handle sensitive patient data. The complexity and scale of the challenges you will face make this position both rewarding and demanding. At Prime Therapeutics, you’ll have the opportunity to work with modern technologies and methodologies, pushing the boundaries of what software can achieve in healthcare.
Initial Screening
reportedFocuses on your resume and basic qualifications.
What to demonstrate
- Focuses on your resume and basic qualifications
- Depth in Technical Question Solving
How to prepare
- Be able to walk your CV end to end in two minutes, and say why this company specifically.
- Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.
Technical Interviews
reportedIncludes coding assessments, system design discussions, and behavioral interviews.
What to demonstrate
- Includes coding assessments, system design discussions, and behavioral interviews
- Depth in Technical Question Solving
How to prepare
- Answer aloud and timed: Describe a time when you optimized an application for performance.
- Answer aloud and timed: Design a system to manage pharmacy benefit transactions.
PracHub editorial advice for the preparation topics above.
Practice Coding
Make sure to practice coding challenges on platforms like LeetCode or HackerRank. Familiarity with common algorithms and data structures is a must.
Understand the Business
Familiarizing yourself with Prime Therapeutics’ business model and how technology supports healthcare will help you align your answers with the company’s goals.
Communicate Clearly
During interviews, articulate your thought process as you solve problems. Clear communication can be as important as technical skills.
Prepare Questions
Prepare thoughtful questions for your interviewers that reflect your interest in the role and company. This demonstrates engagement and curiosity.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Write a function to reverse a linked list.
Write a function to reverse a linked list.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Given a list of integers, find two numbers that sum to a specific target.
Given a list of integers, find two numbers that sum to a specific target.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Merge partitioned event streams into one ordered feed with bounded lateness
The read-model service consumes 64 log partitions carrying about 4,000 events per second in total. Each partition is ordered within itself, but partitions drift by up to 30 seconds, and the activity feed must present a tenant's events in occurred_at order. Produce the merge. State its complexity, the buffer it requires in events and in bytes, what happens when one partition is idle, and what you do with an event that arrives after you have already emitted its position. Payloads average 1 KB.
Approach
- Merge with a min-heap over the 64 partition heads keyed on (occurred_at, event_id): O(log P) per event and O(n log P) overall. The tie-break on event_id is what makes the output deterministic when two partitions carry the same millisecond, which matters because the feed is paginated and a non-deterministic order reorders pages under the reader.
- Emitting the heap head is only correct once every partition has produced everything up to that timestamp, so the emit condition is a watermark: the minimum across partitions of the highest occurred_at seen, less the allowed lateness. Events are held until the watermark passes them, which is what turns individually ordered streams into a jointly ordered one.
- Size the buffer from the lateness rather than guessing: 4,000 events per second times 30 seconds is 120,000 buffered events, and at 1 KB each about 120 MB of heap. That number is the real price of the ordering guarantee and belongs in front of whoever asked for it.
- Handle the idle partition explicitly, because it fails the feed rather than corrupting it: a partition with no traffic never advances its own maximum, so the watermark freezes and output stops entirely. Either every partition emits a periodic idle marker carrying the broker's current time, or the watermark falls back to wall clock for a partition silent beyond a threshold.
Follow-up
- The lateness budget is raised to five minutes. What is the new buffer, and what besides memory changes?
- The consumer restarts. Where does it resume from, and what does the feed look like for the first 30 seconds?
Denormalise tenant onto revisions and backfill it live
resource_revision (revision_id, resource_id, version, actor_user_id, change_kind, patch, request_id, created_at) has 400M rows and no tenant column; tenant_id lives only on resource. Two reads need it: a tenant-scoped audit feed ordered by created_at DESC, and an offboarding purge. Both join back to resource today. Justify adding tenant_id to resource_revision against those two reads, name the anomaly the copy introduces and the constraint that prevents it, then give the ordered migration for a live table taking 1.2k writes/second — the lock each step takes, how the backfill is batched, and where each step stops being reversible. PostgreSQL 16.
Approach
- Justify from the access path rather than from taste. Without the column, the audit feed either scans resource_revision by created_at and discards other tenants' rows, or resolves the tenant's resource_ids first and probes with them — both proportional to the tenant's whole history rather than to one page. With (tenant_id, created_at DESC, revision_id DESC) it is a seek that stops at 50 rows, and the purge becomes a ranged delete instead of a join.
- Name the cost exactly: a second copy of a fact can disagree with the first. Make the disagreement unwritable rather than documented — add UNIQUE (resource_id, tenant_id) on resource so it can serve as a foreign-key target, then FOREIGN KEY (resource_id, tenant_id) REFERENCES resource (resource_id, tenant_id) on the revision table. A revision can then only ever carry its parent's tenant.
- Step one, expand: ALTER TABLE resource_revision ADD COLUMN tenant_id BIGINT NULL, with no default, so it is a catalogue change and no rewrite. It still needs ACCESS EXCLUSIVE for an instant, and that instant queues behind the longest open transaction on the table while every later query queues behind it — set lock_timeout to 2s and retry rather than wait.
- Step two, dual-write: deploy the writer that populates tenant_id on every new revision while reads still use the join. Reversible by redeploying the previous build, because nothing reads the column yet.
Follow-up
- The backfill is half finished and a rollback is required. What state is the table in, and what does the previous build do with a half-populated column?
- How do you verify the backfill actually finished, given rows are still being inserted while it runs?
Write the update path that detects a concurrent edit
resource carries version INT NOT NULL DEFAULT 1. resource_revision holds revision_id, resource_id, version, actor_user_id, change_kind, patch JSONB, request_id, created_at with UNIQUE (resource_id, version). outbox_event holds aggregate_type, aggregate_id, aggregate_version, event_type, payload, status. A PUT carries the version the client read. Write the exact statements for the single transaction that applies the edit, records the revision and enqueues 'resource.updated', and give the handler's branch on zero affected rows. Then say what PostgreSQL 16 does under READ COMMITTED when two of these updates hit one row at once.
Approach
- One transaction, three writes, no network call inside it: UPDATE resource SET title = $3, version = version + 1, updated_at = now() WHERE resource_id = $1 AND tenant_id = $4 AND version = $2; then INSERT the resource_revision row at version $2 + 1; then INSERT the outbox_event row at the same aggregate_version. The event goes to a table rather than a broker because no transaction spans both.
- Branch on the affected-row count before doing anything else. Zero has three causes — stale version, wrong tenant, row gone — so re-read once and map to 409 carrying the current version, or 404 for an id outside the caller's tenant, which also stops the endpoint confirming that another tenant's id exists.
- State the engine behaviour instead of assuming it. Under READ COMMITTED the second UPDATE blocks on the row lock, and when the first commits PostgreSQL re-evaluates the WHERE clause against the newly committed row, so the version predicate now fails and the statement reports zero rows. Under REPEATABLE READ the identical collision raises SQLSTATE 40001 instead, so the handler must fold both shapes into one conflict response.
- Keep UNIQUE (resource_id, version) even though the predicate already serialises writers. It is what makes a lost update unwritable if any other path ever reaches the revision table, and it converts a logic bug into 23505 rather than into a silently missing history row.
Follow-up
- A client sends the version it read ten minutes ago and the resource has moved three versions. What is in your 409 so it can resolve the conflict without a full re-fetch?
- Two editors, two disjoint fields, no overlap. Does your answer still refuse the second write, and should it?
Explain the difference between an abstract class and an interface in Java.
Explain the difference between an abstract class and an interface in Java.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
What are the principles of RESTful API design?
What are the principles of RESTful API design?
Approach
- Say who the caller is and what they do when the call fails halfway.
- Define the identity of a request so a retry cannot double-apply it.
- Separate accepted, pending, failed and confirmed; they are different facts.
- Design the error taxonomy before the success shape; callers branch on it.
Follow-up
- What happens if the caller retries after a timeout?
- How does a client discover it is on an old version of this contract?
Design a system to manage pharmacy benefit transactions.
Design a system to manage pharmacy benefit transactions.
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
How would you ensure high availability in a web application?
How would you ensure high availability in a web application?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Given a dataset, how would you identify anomalies?
Given a dataset, how would you identify anomalies?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
How would you approach debugging a system that produces inconsistent results?
How would you approach debugging a system that produces inconsistent results?
Approach
- Establish what changed and when, before forming any theory.
- Pick a bisection that eliminates candidates whichever way it turns out.
- Check the instrumentation before believing the symptom.
- Separate the trigger from the cause; the deploy is rarely the bug.
Follow-up
- What would you look at first, and what would it rule out?
- How would you tell a cause from a coincidence here?
Built from the rounds and topics Prime Therapeutics candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Prime Therapeutics loop
- Write out the reported sequence: Initial Screening, Technical Interviews.
- For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.
Deliverable: A one-page map of the 2 reported rounds, with the weakest marked.
02Work Technical Question Solving
- Spend the session on Technical Question Solving, which Prime Therapeutics candidates report being tested on.
- Write one worked example in Technical Question Solving and time yourself on it.
Deliverable: One timed worked example in Technical Question Solving.
03Work Behavioral Interviewing
- Spend the session on Behavioral Interviewing, which Prime Therapeutics candidates report being tested on.
- Write one worked example in Behavioral Interviewing and time yourself on it.
Deliverable: One timed worked example in Behavioral Interviewing.
04Work Communication Skills
- Spend the session on Communication Skills, which Prime Therapeutics candidates report being tested on.
- Write one worked example in Communication Skills and time yourself on it.
Deliverable: One timed worked example in Communication Skills.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Explain the difference between an abstract class and an interface in Java.
- Answer aloud, timed: What are the principles of RESTful API design?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: System Design / Architecture
- Answer aloud, timed: Design a system to manage pharmacy benefit transactions.
- Answer aloud, timed: How would you ensure high availability in a web application?
Deliverable: Spoken answers to 2 reported System Design / Architecture question(s), under time.
07Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a challenging project and how you handled obstacles.
- Answer aloud, timed: How do you prioritize tasks when you have multiple deadlines?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
Expand any day for tasks and deliverables. Your progress is saved on this device.
Behavioural rounds judge the decision you made and what it cost.
Describe a time when you optimized an application for performance.
Describe a time when you optimized an application for performance.
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
Describe a challenging project and how you handled obstacles.
Describe a challenging project and how you handled obstacles.
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
How do you prioritize tasks when you have multiple deadlines?
How do you prioritize tasks when you have multiple deadlines?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
- 01
Describe a time when you optimized an application for performance.
- 02
Describe a challenging project and how you handled obstacles.
- 03
How do you prioritize tasks when you have multiple deadlines?
How difficult are the interviews at Prime Therapeutics?
The interviews can be challenging, particularly the technical portions. However, candidates who prepare thoroughly and understand the core principles of software engineering typically perform well.
Prime Therapeutics Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often demonstrate a strong grasp of technical skills, an ability to collaborate effectively, and a clear alignment with Prime Therapeutics' values and mission.
Prime Therapeutics Software Engineer candidate reports ↗What is the culture like at Prime Therapeutics?
The culture emphasizes teamwork, innovation, and a commitment to improving healthcare outcomes. Candidates who thrive in collaborative environments typically do well.
Prime Therapeutics Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The interview process can last several weeks, depending on the number of candidates and scheduling logistics. Candidates should be prepared for multiple rounds of interviews.
Prime Therapeutics Software Engineer candidate reports ↗Are there remote work options available?
Prime Therapeutics offers flexible work arrangements, including remote and hybrid options, depending on the role and team needs.
Prime Therapeutics Software Engineer candidate reports ↗What topics does Prime Therapeutics test in interviews?
Prime Therapeutics interviews most often cover Stakeholder Communication, Communication Skills, Data-Driven Decision Making, Problem Solving, and Healthcare domain knowledge (PBM). The exact emphasis depends on the specific role you apply for.
Prime Therapeutics Software Engineer candidate reports ↗Sources & methodology 3 sources ↗
No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.
- 01Prime Therapeutics Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
Candidate reports · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
PracHub page · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
PracHub page · Accessed 2026-09-22
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