Software Senior Architect Lead – Non-Functional Engineering (NFE)

FIS; Warszawa; Hybrid; PLN 176,000 - 281,000; Full time

Benefits offered by this job

Impact in fintech

Learning opportunities

Inclusive environment

Community involvement

Competitive compensation

Job summary

FIS is seeking an experienced Software Architect Lead for Non-Functional Engineering (NFE) in Poland (hybrid). The role focuses on performance of large-scale Java systems, profiling, tuning, and leadership in load testing and optimization.

You will work with the NFE team to profile, measure, and prove optimisations that improve throughput, latency and cost, while guiding code-level improvements and architectural decisions.

Qualifications

• Substantial experience as a performance architect or senior performance engineer, optimising large-scale, high-throughput Java systems running in production.
• Deep, hands-on expertise in Java profiling tools to isolate CPU, memory, lock and I/O bottlenecks.
• Proven ability to analyse thread dumps and reason rigorously about concurrency, identifying deadlocks, contention and thread starvation.
• Strong command of JVM garbage collection internals with real experience interpreting GC logs and tuning heap sizing.
• Confidence reading database execution plans and tuning SQL, indexes and schema design to eliminate data-layer bottlenecks.

Responsibilities

• Profile Java applications end to end across CPU, memory, threads and I/O to isolate hot paths.
• Analyse thread dumps to diagnose lock contention and reshape the concurrency model.
• Own garbage collection analysis and JVM tuning to reduce pause times and stabilize latency under load.
• Read database execution plans to tune expensive SQL and indexing strategies.
• Work directly in the codebase to propose, implement and validate code-level optimisations.
• Design and lead load, stress, soak and failover campaigns and drive performance investigations.

Skills

Java profiling

Thread dumps analysis

GC tuning

DB plan reading

Developer mindset

Tools

Java Flight Recorder

async-profiler

JProfiler

YourKit

Oracle

PostgreSQL

Job description

Type Of Hire

Experienced (relevant combo of work and education)

Position Type

Full time

Software Senior Architect Lead – Non-Functional Engineering (NFE)

Location~ Poland (hybrid)

Are you curious, motivated, and forward-thinking? At FIS you’ll have the opportunity to work on some of the most challenging and relevant issues in financial services and technology. Our talented people empower us, and we believe in being part of a team that is open, collaborative, entrepreneurial, passionate and above all fun.

About The Team

You will be joining FIS' Non-Functional Engineering (NFE) team, the group accountable for the performance, scalability and resilience of the OPF payments product line. Operating globally across EMEA, the US, APAC and India, we define and validate the non-functional requirements behind mission‑critical payment platforms, engineer the load, stress and endurance testing that proves them, and translate measured evidence into tuning, sizing and architecture decisions. Our purpose is straightforward~ ensure FIS products are fast, predictable and resilient at real production scale, long before a customer ever feels a bottleneck.

What You Will Be Doing

As a Software Architect, you will own the deep technical analysis that explains how our payment platforms behave under load and, more importantly, how to make them significantly faster.

You will profile running systems, dissect their runtime behaviour and challenge design decisions, working shoulder to shoulder with the engineers who build the product.

You will not simply report findings; you will prototype, measure and prove the optimisations that turn them into quantifiable gains in throughput, latency and cost.

This role will suit someone with a developer mindset, who enjoys reading code as much as reading metrics.

• Profile Java applications end to end across CPU, memory, threads and I/O, using tools such as Java Flight Recorder, async-profiler and JProfiler, to isolate the hot paths that constrain throughput
• Analyse thread dumps to diagnose lock contention, deadlocks, thread‑pool exhaustion and blocking I/O, then reshape the concurrency model to remove the constraint
• Own garbage collection analysis and JVM tuning, sizing heaps, selecting and configuring collectors and reducing allocation pressure, to cut pause times and stabilise latency under sustained load
• Read and interpret database execution plans to tune expensive SQL, correct indexing and join strategies, and resolve contention and locking at the data layer
• Work directly in the codebase alongside development teams to propose, implement and validate code‑level optimisations, and embed performance thinking into design reviews, coding standards and delivery pipelines
• Design and lead load, stress, soak and failover campaigns, and drive performance investigations during customer escalations, converting every finding into a permanent fix, a sizing recommendation or a new predictive test

What You Bring

Substantial experience as a performance architect or senior performance engineer, optimising large‑scale, high‑throughput Java systems running in production

• Deep, hands‑on expertise in Java profiling (Java Flight Recorder, async-profiler, JProfiler or YourKit) to isolate CPU, memory, lock and I/O bottlenecks
• Proven ability to analyse thread dumps and reason rigorously about concurrency, identifying deadlocks, contention and thread starvation and prescribing the fix
• Strong command of JVM garbage collection internals (G1, ZGC, Shenandoah, CMS), with real experience interpreting GC logs and tuning heap sizing and allocation behaviour
• Confidence reading database execution plans (Oracle or PostgreSQL) and tuning SQL, indexes and schema design to eliminate data‑layer bottlenecks
• A developer mindset~ you are at home in the codebase, read and write production‑quality Java, and would rather prove an optimisation by building and measuring it than by describing it

What We Offer You

At FIS, you can grow your career as far as you want to take it. Here’s what else we offer~

• Opportunities to make an impact in fintech
• Personal and professional learning
• Inclusive, diverse work environment
• Resources to give back to your community
• Competitive salary and benefits

FIS is committed to providing its employees with an exciting career opportunity and competitive compensation. The pay range for this fulltime position is 175,900.00/281,440.00 PLN Annual and reflects the minimum and maximum target for new hire salaries for this position based on the posted role, level, and location. Within the range, actual individual starting pay is determined by additional factors, including jobrelated skills, experience, and relevant education or training. Any changes in work location will also impact actual individual starting pay. Please consult with your recruiter about the specific salary range for your preferred location during the hiring process.

Privacy Statement

FIS is committed to protecting the privacy and security of all personal information that we process in order to provide services to our clients. For specific information on how FIS protects personal information online, please see the Online Privacy Notice.

Sourcing Model

Recruitment at FIS works primarily on a direct sourcing model; a relatively small portion of our hiring is through recruitment agencies. FIS does not accept resumes from recruitment agencies which are not on the preferred supplier list and is not responsible for any related fees for resumes submitted to job postings, our employees, or any other part of our company.

#pridepass