Senior Software Engineer (Python)

Kunai•Houston, TX

23h

About The Position

Kunai builds full-stack technology solutions for banks, credit and payment networks, infrastructure providers, and their customers. 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. 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 greenfield-style work inside a high-stakes, high-volume environment & a rare combination of modernization impact and real production scale.

Requirements

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)

Nice To Haves

Experience in financial services, payments, fraud detection, or other high-stakes transactional systems is a plus

Responsibilities

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