Full Stack Engineer
littlefish
Software Engineering
Sterling, VA, USA · Remote
Posted on Apr 23, 2026
About littlefish
We are a fast-growing fintech startup powering financial institutions across the African continent through our full stack enterprise platform. Proudly rooted in South African values but with a vision that transcends borders, we provide a single stack that powers merchant acquiring across payments, onboarding, engagement, commerce and operations.
Help us enable every enterprise, connect every merchant, and make every transaction intelligent. Your work will create lasting change in how financial services are delivered
Role Summary
The Full Stack Engineer is a core contributor to the design, development, and delivery of the littlefish platform. This is a hands-on, high-ownership role that spans backend services, web frontends, and cross-platform mobile applications. You will work closely with Product, Design, and Engineering peers to ship well-architected features across our entire stack — from robust C# / .NET APIs and event-driven integrations to React web interfaces and Flutter mobile experiences.
This role sits at the intersection of backend depth and full-stack breadth. We're looking for engineers who take pride in clean architecture, think carefully about integration design, and are comfortable contributing to solution design discussions — not just writing code to spec.
Key Responsibilities
Solution Design & Architecture
Participate actively in technical design discussions and propose pragmatic, well-reasoned solutions.
Produce clear solution design documents, architecture diagrams, and API contracts ahead of implementation.
Evaluate trade-offs between service boundaries, data models, integration patterns, and build vs. buy decisions.
Champion engineering best practices: observability, resilience, documentation, and continuous improvement.
Senior engineers are expected to drive end-to-end solution design for major features and lead cross-functional technical design reviews.
Backend Development
Design, build, and maintain scalable C# / .NET services and APIs that power the littlefish platform.
Own the full request lifecycle: API design, business logic, data persistence, observability, and error handling.
Implement and maintain integrations with payment gateways, banking partners, and third-party APIs — REST, webhooks, and message-driven.
Ensure services meet the performance, reliability, and security requirements appropriate for a regulated fintech environment.
Write clean, testable code with meaningful unit and integration test coverage.
Contribute to and uphold engineering standards around code review, documentation, and service design.
Frontend & Mobile Development
Build and maintain web frontends using React and TypeScript, following component-driven design principles.
Develop cross-platform mobile features using Flutter and Dart for the littlefish merchant and consumer applications.
Collaborate with Product and Design to translate requirements into polished, accessible user interfaces.
Maintain consistency across platforms through shared design systems and component libraries.
Optimise for performance, usability, and responsiveness across device types.
Integrations
Design and implement integrations with external financial services including payment processors, core banking systems, and third-party platforms.
Build resilient integration patterns: idempotency, retry logic, event-driven messaging, and circuit breakers.
Ensure data contracts are well-defined, versioned, and backwards-compatible.
Contribute to API-first design using OpenAPI / Swagger standards.
Infrastructure & Platform Awareness
Work confidently within our GCP-hosted, Kubernetes-orchestrated infrastructure.
Understand and contribute to containerised deployment pipelines using Docker and Kubernetes (GKE).
Engage with platform tooling: CI/CD pipelines (GitHub Actions / Cloud Build), Cloud Storage, managed databases, and Secret Manager.
Write services with observability in mind — structured logging, distributed tracing, and alerting.
Collaborate with DevOps / platform engineering on deployment configurations, resource sizing, and incident response.
Collaboration & Delivery
Work in cross-functional squads alongside Product Managers, Designers, QA Engineers, and DevOps.
Participate in agile ceremonies: sprint planning, stand-ups, retrospectives, and technical reviews.
Mentor intermediate engineers through code review and pair programming.
Contribute to internal technical documentation, runbooks, and incident post-mortems.
Skills and Qualifications
Experience
5 – 7+ years of professional software development experience, with clear progression from intermediate to senior level.
Strong, demonstrable proficiency in C# and .NET — this is your primary backend language.
Hands-on experience building and consuming REST APIs and third-party integrations (payment APIs, banking APIs, or similar).
Working experience with React and TypeScript for web frontend development.
Familiarity with Flutter and Dart for cross-platform mobile development.
Experience working with relational databases (SQL Server / PostgreSQL), query optimisation, and ORM usage.
Exposure to GCP (or equivalent cloud platform) and containerisation with Docker and Kubernetes.
Proven ability to contribute to or lead solution design discussions, with the ability to document decisions clearly.
Technical Skills
Proficient in C# / .NET 6+, ASP.NET Core, Entity Framework Core.
Strong grasp of RESTful API design, HTTP semantics, OAuth 2.0 / JWT, and service-to-service auth.
Frontend development with React, TypeScript, HTML5 / CSS3.
Mobile development with Flutter and Dart.
Cloud & infrastructure: GCP, Kubernetes (GKE), Docker, CI/CD pipelines (GitHub Actions / Cloud Build), GCP Secret Manager, Cloud Storage.
Messaging and event-driven patterns: RabbitMQ, Azure Service Bus, or GCP Pub/Sub.
Observability tooling: structured logging, distributed tracing, application monitoring.
Familiarity with OpenAPI / Swagger for API documentation and contract design.
Soft Skills & Leadership
Ability to simplify complexity — communicate technical decisions clearly to both engineers and non-technical stakeholders.
Strong problem-solving and root-cause analysis skills; comfortable debugging distributed systems.
Able to proactively raise risks, say no with reasoning, and defend architectural decisions constructively.
Bias for clarity, ownership, and quality — you finish what you start and leave things better than you found them.
Collaborative and communicative in a fast-paced, cross-functional team environment.
Senior engineers are expected to mentor peers and contribute to a culture of engineering excellence.
To apply, please send your resume and a short cover letter to talent@littlefishapp.com
