Interview guides · Syntes

Syntes Software Engineer Interview Guide

Syntes Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

A Software Engineer at Syntes plays a critical role in designing, developing, and maintaining high-integrity software systems that power our next-generation healthcare and medical technology solutions. Working at the intersection of advanced software engineering and life-changing technology, engineers in this role build scalable architectures, modern cloud infrastructure, and robust systems integrations. The work you do directly impacts patient outcomes, clinical workflows, and the overall safety and efficiency of medical technologies globally. In this position, you will tackle complex technical challenges ranging from low-level systems programming to highly scalable cloud-native microservices.

This guide is scoped to a Software Engineer candidate at Syntes.

Focus areas

Behavioral Interviewing
Communication Skills (Technical Communication)
System Design

The Syntes interview process

Syntes candidates report 4 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Digital Screening

Asynchronous screening on HireVue where you record video responses to behavioral and introductory questions.

What to demonstrate

Asynchronous screening on HireVue where you record video responses to behavioral and introductory questions
Depth in Behavioral Interviewing

How to prepare

Answer aloud and timed: Why do you want to work at Syntes, and how does your background support this role?
Answer aloud and timed: Describe a stressful situation you faced in a past project and how you managed it.

Recruiter Call

Conversational screening with a recruiter to discuss your background, expectations, and interest in Syntes.

What to demonstrate

Conversational screening with a recruiter to discuss your background, expectations, and interest in Syntes
Depth in Behavioral Interviewing

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 Conversations

Discussions with hiring managers and team engineers, including live coding and system design.

What to demonstrate

Discussions with hiring managers and team engineers
Including live coding and system design

How to prepare

Answer aloud and timed: How do you handle constructive criticism or conflicting technical opinions from your peers?
Answer aloud and timed: Explain the difference between a process and a thread, and discuss when you would use multi-threading versus multitasking.

Panel Interview

Comprehensive panel interview featuring a presentation of a previous project followed by structured technical and behavioral sessions.

What to demonstrate

Comprehensive panel interview featuring a presentation of a previous project followed by structured technical and behavioral sessions
Depth in Behavioral Interviewing

How to prepare

Answer aloud and timed: How do you implement and manage transactions in a microservices architecture?
Answer aloud and timed: Walk me through how you would optimize a Java application experiencing memory leaks or performance bottlenecks in production.

Where candidates lose points

Master the HireVue Screen

Treat the asynchronous video interview with the same professionalism as a live conversation. Ensure your lighting and audio are clear, utilize the practice attempts to get comfortable with the platform, and keep your answers structured and concise (aim for under 3 minutes per question).

Emphasize the 'How' Over the 'What'

When answering technical or system-related questions, explain your thought process clearly. Our engineers value a candidate who can talk through trade-offs, discuss edge cases, and explain how they arrived at a solution, even if they don't have the perfect syntax memorized on the spot.

Showcase Your Passion for Healthcare Tech

Syntes is dedicated to improving lives through technology. Expressing genuine enthusiasm for the mission and showing an eagerness to learn about our specific domain will resonate strongly with your interviewers.

Questions & practice

Explain the difference between a process and a thread, and discuss when you would use multi-threading versus m

Medium · Technical & System Fundamentals

Explain the difference between a process and a thread, and discuss when you would use multi-threading versus multitasking.

Approach

Say what the runtime actually does before reasoning about the code.
Name what is shared across threads and what owns each piece of state.
Identify the window where an invariant is briefly untrue.
Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

What happens if two callers reach this at the same time?
Where could this allocate more than you expect?

Explain the concept of immutability in languages like Java or C++, and why it is beneficial.

Medium · Technical & System Fundamentals

Approach

Say what the runtime actually does before reasoning about the code.
Name what is shared across threads and what owns each piece of state.
Identify the window where an invariant is briefly untrue.
Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

What happens if two callers reach this at the same time?
Where could this allocate more than you expect?

Track a rolling failure rate per destination for circuit decisions

Easy · sliding window · ring buffer · circuit breaker

The egress service delivers about 1,500 webhooks per second across roughly 40,000 destinations, each call bounded by a 10 second timeout. Maintain, per destination, the failure rate over the trailing 60 seconds so a caller can ask before dispatch whether the circuit should open. Attempts arrive as (destination_id, finished_at_ms, outcome). Requirement: amortised O(1) per attempt, with total memory bounded by the destination count rather than by traffic. Give the structure, its exact memory, and the rule that stops a destination with three attempts from opening a circuit.

Approach

Name the exact-deque version and then reject it as the default. Holding timestamps and advancing a tail pointer past anything older than now minus 60 seconds is a correct two-pointer window at amortised O(1) per attempt, but its memory tracks in-window traffic, so one destination in a retry storm holds hundreds of thousands of entries while thousands of quiet destinations hold none.
Use a ring of 60 one-second buckets per destination, each bucket a pair of counters for attempts and failures. On an attempt, advance the ring by the elapsed whole seconds, zeroing at most min(elapsed, 60) buckets, then increment the head. That is amortised O(1) with a fixed footprint per destination.
State the footprint: 60 buckets times two 4-byte counters is 480 bytes of payload per destination, so 40,000 destinations is roughly 20 to 25 MB with per-entry overhead, bounded by the catalogue rather than by the rate. The cost is granularity, since the oldest bucket ages out in whole seconds, which is far tighter than the decision needs.
Require a minimum sample before the circuit may open. A destination with three attempts and three failures reads as 100 percent and is not evidence; a floor of roughly 20 attempts in the window makes the ratio meaningful, and below that floor use a run of consecutive failures as the trigger instead.

Follow-up

The fleet is 30 instances and each sees roughly a thirtieth of a destination's traffic. Where does the rate actually live, and what does a per-instance answer get wrong?
A destination answers in 9.5 seconds and succeeds. It is not failing but it is consuming your per-destination concurrency. What signal should open the circuit here?

Write the update path that detects a concurrent edit

Medium · optimistic concurrency · transactional outbox · audit history

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?

Hold a per-tenant active cap against concurrent creates

Hard · write skew · isolation levels · constraints

A tenant on the standard plan may hold at most 50 resources with status='active'. The create handler runs SELECT count(*) FROM resource WHERE tenant_id = $1 AND status = 'active', compares to 50, then inserts. Two creates arrive 3 ms apart on different instances and the tenant lands at 51. Name the anomaly, say whether PostgreSQL 16 READ COMMITTED or REPEATABLE READ prevents it and why, then give an implementation that holds the cap at READ COMMITTED with the exact statements. Finally, say what changes when the cap is 'at most one running export per tenant' on job_run.

Approach

Name it: write skew. The two transactions read an overlapping set and write disjoint rows, so there is no row-level conflict for the engine to detect and each commit is individually legal.
Rule out the levels precisely. READ COMMITTED takes a fresh snapshot per statement and takes no lock on the counted rows, so both see 49. PostgreSQL's REPEATABLE READ is snapshot isolation: it removes non-repeatable reads and phantoms within the snapshot but still admits write skew, because the anomaly is not a re-read of a changed row, it is a read of a set that a concurrent transaction invalidates. Only SERIALIZABLE closes it, by tracking the read dependency and aborting one transaction with SQLSTATE 40001 — a guarantee that exists only if the application re-runs the whole transaction from the read.
Convert the set predicate into a single-row conflict: keep tenant.active_resource_count and run UPDATE tenant SET active_resource_count = active_resource_count + 1 WHERE tenant_id = $1 AND active_resource_count < 50 in the same transaction as the INSERT. Zero affected rows is the cap, returned as 409. The row lock serialises the decision at any isolation level, and contention is bounded to one tenant's row — which is also the fair-scheduling unit, unlike a global counter that would convoy every tenant behind one row.
State the cost you just took on: a counter is a second source of truth that can drift, so every path that changes status must adjust it inside the same transaction, and a periodic reconciliation has to exist, with resource_revision as the authority for what the count should have been.

Follow-up

A resource moves from archived back to active. Which statements change, and what breaks if the counter update and the status change land in different transactions?
The cap becomes plan-dependent and a plan can change mid-month. Where does the number 50 live, and who reads it?

How do you implement and manage transactions in a microservices architecture?

Medium · Technical & System Fundamentals

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?

Walk us through your approach to testing software. How do you ensure high test coverage for mission-critical a

Medium · Testing, Quality & Systems Integration

Walk us through your approach to testing software. How do you ensure high test coverage for mission-critical applications?

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?

How do you go about identifying, tracking, and resolving a critical bug in a production environment using tool

Medium · Testing, Quality & Systems Integration

How do you go about identifying, tracking, and resolving a critical bug in a production environment using tools like Jira?

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?

How do you design software to comply with strict regulatory standards without sacrificing development velocity

Medium · Testing, Quality & Systems Integration

How do you design software to comply with strict regulatory standards without sacrificing development velocity?

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?

Walk me through how you would optimize a Java application experiencing memory leaks or performance bottlenecks

Medium · Technical & System Fundamentals

Walk me through how you would optimize a Java application experiencing memory leaks or performance bottlenecks in production.

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?

Suggested practice checklist

Built from the rounds and topics Syntes candidates report.

Day 1 — Map the Syntes loop

Write out the reported sequence: Digital Screening, Recruiter Call, Technical Conversations, Panel Interview.
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 4 reported rounds, with the weakest marked.

Day 2 — Work Behavioral Interviewing

Spend the session on Behavioral Interviewing, which Syntes 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.

Day 3 — Work Communication Skills (Technical Communication)

Spend the session on Communication Skills (Technical Communication), which Syntes candidates report being tested on.
Write one worked example in Communication Skills (Technical Communication) and time yourself on it.

Deliverable: One timed worked example in Communication Skills (Technical Communication).

Day 4 — Work System Design

Spend the session on System Design, which Syntes candidates report being tested on.
Write one worked example in System Design and time yourself on it.

Deliverable: One timed worked example in System Design.

Day 5 — Answer out loud: Behavioral & Value Alignment

Answer aloud, timed: Why do you want to work at Syntes, and how does your background support this role?
Answer aloud, timed: Describe a stressful situation you faced in a past project and how you managed it.

Deliverable: Spoken answers to 2 reported Behavioral & Value Alignment question(s), under time.

Day 6 — Answer out loud: Technical & System Fundamentals

Answer aloud, timed: Explain the difference between a process and a thread, and discuss when you would use multi-threading versus multitasking.
Answer aloud, timed: How do you implement and manage transactions in a microservices architecture?

Deliverable: Spoken answers to 2 reported Technical & System Fundamentals question(s), under time.

Day 7 — Answer out loud: Testing, Quality & Systems Integration

Answer aloud, timed: Walk us through your approach to testing software. How do you ensure high test coverage for mission-critical applications?
Answer aloud, timed: How do you go about identifying, tracking, and resolving a critical bug in a production environment using tools like Jira?

Deliverable: Spoken answers to 2 reported Testing, Quality & Systems Integration question(s), under time.