Senior Software Engineer (Python)

Kunai; Houston (TX); On-site; USD 125,000 - 180,000; Full time

Benefits offered by this job

Competitive compensation

Flexible work arrangements

Professional development opportunities

Job summary

Kunai in Houston seeks engineers to decompose a large legacy network into domain-driven, standalone services. You’ll design service boundaries, build event pipelines with Kafka, and re‑architect data flows with S3, Redis caching, and in‑memory systems.

You will write production Python, use AWS serverless tooling, and collaborate across teams to balance throughput, reliability, and cost in a cloud‑native environment.

Qualifications

• Production experience with Python.
• Experience building and operating high-throughput services.
• Experience with event-driven architectures and Kafka.
• Proficiency with AWS serverless services (Lambda, S3).
• Familiarity with in-memory caching (Redis).

Responsibilities

• Design, build, and own standalone services extracted from legacy systems.
• Build event-driven, serverless architectures using AWS Lambda.
• Design reliable messaging pipelines with Kafka.
• Optimize data flows with S3, queuing, and Redis-based matching.
• Collaborate to define domain models and service contracts.

Skills

Python

Event-driven architectures

High-throughput systems

Cross-functional collaboration

Cloud-native design

Education

Bachelor's degree

Tools

AWS Lambda

Kafka

S3

Redis

Job description

Kunai builds full‑stack technology solutions for banks, credit and payment networks, infrastructure providers, and their customers. Together, we are changing the world’s relationship with financial services. At Kunai, we help our clients modernize, capitalize on emerging trends, and evolve their business for the coming decades by remaining tech‑agnostic and human‑centered.

Our group owns the modernization and scalability of several mission‑critical systems, including money transfer, early warning/fraud detection, settlement scalability, and debit, as we migrate from on‑prem infrastructure to fully cloud‑native AWS services. This is a hands‑on engineering team: our core focus is building software, not managing vendor platforms. We’re looking for engineers who want to design and ship new systems, not administer someone else’s.

The Opportunity

Our current network infrastructure has reached capacity and is nearing the end of its useful lifespan. Rather than scale the monolith further, we’re decomposing it, extracting functionality into well‑defined domains and standalone services, backed by event‑driven architecture and modern AWS tooling. You’ll be part of the team building this from the ground up: designing service boundaries, building event pipelines with Kafka, and re‑architecting how data flows through the system (e.g., files staged in S3, queued, and matched via an in‑memory cache like Redis). This is green‑field‑style work inside a high‑stakes, high‑volume environment—a rare combination of modernization impact and real production scale.

What You’ll Do

• Design, build, and own standalone services extracted from legacy monolithic systems, organized around clear domain boundaries
• Build event‑driven, serverless architectures using AWS Lambda and related AWS services
• Use Kafka to design reliable, high‑throughput messaging and event streaming pipelines
• Build and optimize data flows involving file ingestion, S3 staging, queuing, and cache‑based matching (e.g., Redis)
• Help re‑architect high‑transaction‑volume systems (money transfer, early warning/fraud detection, settlement scalability, debit) for cloud‑native scalability
• Diagnose and resolve infrastructure capacity constraints, and design services that relieve pressure on network and systems that have reached the end of their useful lifespan
• Write production Python code as the primary language for new services
• Incorporate AI‑assisted development practices (Claude) into your day‑to‑day workflow to accelerate design, coding, and review
• Collaborate cross‑functionally to define domain models and service contracts as systems are decomposed
• Participate in architecture decisions balancing throughput, reliability, and cost in a cloud‑native environment

What We’re Looking For

• Strong professional experience building and operating large‑scale, high‑transaction‑volume, high‑throughput services
• Proven experience with Python in production environments
• Hands‑on experience with event‑driven architectures, including Kafka (or equivalent streaming/messaging platforms)
• Experience with AWS serverless services, particularly Lambda, and broader AWS cloud‑native tooling (S3, etc.)
• Experience with in‑memory caching/matching systems (e.g., Redis)
• Experience decomposing monolithic systems into domain‑driven, standalone services
• Comfort working in a fast‑moving, engineering‑first culture someone who wants to build, not just maintain
• Interest in and openness to AI‑assisted development workflows (e.g., using Claude to accelerate coding, review, and design)
• Experience in financial services, payments, fraud detection, or other high‑stakes transactional systems is a plus

Why This Role

• Direct ownership of systems being rebuilt from the ground up, not just maintained
• Work on systems with real transaction volume and real performance stakes
• A team culture centered on engineering and building, not vendor management
• Early adoption of AI‑first development practices as a core part of how the team works

Benefits

We are proud to offer our employees a range of benefits, including competitive compensation, professional development opportunities, and flexible work arrangements, all designed to help them thrive. As we continue to expand, we remain committed to cultivating an environment where people feel valued, have a voice, and are given the tools to grow—both personally and professionally—while pushing the boundaries of innovation in the fintech industry.

Minimum Degree Required

• Bachelor’s degree, in lieu of a degree, demonstrating in addition to the minimum years of experience required for the role, three years of specialized training and/or progressively responsible work experience in technology for each missing year of college is required.