CleanCode Agency

## About Us

We are building the next generation of financial infrastructure - programmable, transparent, and accessible to everyone. Our platform processes millions of transactions daily, bridging traditional finance with decentralized protocols.

## The Role

We're looking for a Senior Backend Engineer to design, build, and scale the systems that power our payment rails, on-chain settlement layer, and API platform. You'll work at the intersection of high-performance distributed systems and blockchain technology, shipping code that moves real money.

## What You'll Do

- Design and implement low-latency microservices in Go that handle payment processing, ledger management, and transaction orchestration.

- Build and maintain production-grade RESTful and gRPC APIs serving thousands of requests per second to internal teams, partners, and third-party developers.

- Own the HTTP gateway layer - rate limiting, authentication (OAuth 2.0 / API keys), request validation, and observability middleware.

- Architect event-driven pipelines using Kafka or NATS for real-time transaction streaming, reconciliation, and compliance monitoring.

- Contribute to our internal blockchain indexer — parsing blocks, decoding contract events, and maintaining a queryable transaction history.

- Collaborate with the security and compliance team on KYC/AML data flows, audit logging, and regulatory reporting.

## What We're Looking For

- 5+ years of professional backend engineering experience, with at least 3 years writing production Go.

- Strong understanding of HTTP/1.1 and HTTP/2 semantics, TLS, connection pooling, and API design best practices.

- Hands-on experience with blockchain technologies — interacting with nodes (JSON-RPC / WebSocket), parsing transactions, or integrating wallets and custodians.

- Experience with PostgreSQL (or CockroachDB) at scale — schema design, query optimization, migrations, and replication.

- Working knowledge of Docker, Kubernetes, and CI/CD pipelines in a cloud environment (AWS, GCP, or Azure).

- Comfort with distributed systems concepts: consensus, idempotency, eventual consistency, saga patterns.

- Understanding of financial concepts: double-entry bookkeeping, settlement, float management, and reconciliation.

## Nice to Have

- Contributions to open-source Go libraries or blockchain tooling.

- Knowledge of zero-knowledge proofs or privacy-preserving payment systems.

- Prior experience at a regulated fintech, neobank, or crypto exchange.

## Tech Stack

Go, FastHTTP, Kubernetes, Docker

## What We Offer

- Fully remote with optional co-working budget.

- Annual learning stipend for conferences, courses, and certifications.

- Hardware budget for your ideal dev setup.

- Flexible PTO and company-wide recharge weeks.

- Early-stage impact — your architectural decisions will shape the platform for years.

We're hiring a Senior AdTech Engineer to design and scale our advertising technology platform, focusing on real-time ad serving, bidding infrastructure, and measurement systems.

What You'll Do

Build and optimize high-throughput, low-latency systems for programmatic ad delivery and RTB integrations. Develop audience targeting and segmentation pipelines using first-party and contextual data. Design privacy-compliant attribution and measurement frameworks. Collaborate with product and data science teams and mentor junior engineers.

What You Bring

4+ years in software engineering, with 3+ years in adtech or related domains. Strong backend skills (Go, Java, Python, or Rust) and experience with distributed systems, stream processing, and cloud infrastructure. Deep knowledge of RTB, OpenRTB, header bidding, and programmatic advertising. Solid SQL and data warehousing experience. Familiarity with privacy regulations (GDPR, ePrivacy) and emerging cookieless solutions is a strong plus.

What We Offer

Competitive compensation, flexible work arrangements, and the chance to shape a platform reaching millions of users daily.

We're looking for an experienced Go Engineer to join our team and help build, scale, and maintain our payment gateway platform. You'll work on high-throughput, low-latency systems that process financial transactions in real time, ensuring reliability, security, and compliance at every layer.

What You'll Do

Design, develop, and maintain core payment processing services in Go. Build and optimize APIs for merchant integration, transaction routing, and settlement workflows. Implement secure communication with card networks, acquiring banks, and alternative payment providers.

 Ensure PCI DSS compliance across services and infrastructure. Improve system observability through structured logging, metrics, and distributed tracing. 

Participate in architecture decisions, code reviews, and incident response. 

Collaborate with product, risk, and compliance teams to ship features that meet regulatory requirements.

What We're Looking For

3+ years of professional experience writing production Go. Strong understanding of concurrency patterns (goroutines, channels, context propagation). 

Experience building and operating microservices in a distributed environment. 

Familiarity with payment industry concepts such as authorization, capture, refunds, chargebacks, and tokenization. 

Solid grasp of relational databases (PostgreSQL preferred) and transactional integrity. 

Experience with message brokers (Kafka, RabbitMQ, or NATS). 

Comfort working with Docker, Kubernetes, and CI/CD pipelines. Understanding of security best practices: encryption at rest and in transit, secret management, and secure coding.

Nice to Have

Prior experience in fintech, payments, or banking. Familiarity with PCI DSS, PSD2, or 3D Secure protocols.

 Experience with gRPC and Protocol Buffers. 

Knowledge of event-driven architectures and CQRS/event sourcing. Contributions to open-source Go projects.

Tech Stack

Go, PostgreSQL, Redis, Kafka, gRPC, Kubernetes, Prometheus, Grafana, Terraform.

What We Offer

Competitive salary and equity participation.

 Flexible remote or hybrid work arrangement.

 Budget for conferences, courses, and certifications. 

Modern engineering culture with a focus on ownership, autonomy, and continuous improvement. 

The opportunity to work on systems that move real money at scale.

As a Tech Support Developer, you will act as a high-level technical escalation point. You’ll spend your time investigating complex issues that require reading (and occasionally writing) code to solve. You are a developer by trade but a problem-solver by nature.

Key Responsibilities

• Deep-Dive Troubleshooting: Investigate complex technical issues reported by users by analyzing logs, querying databases, and reviewing application code.
• Bug Resolution: Identify, reproduce, and document software bugs. You will submit pull requests for hotfixes and minor improvements to the production codebase.
• Tooling & Automation: Build internal scripts and dashboards (Go, Python, or Node.js) to automate repetitive support tasks and monitor system health.
• Technical Advocacy: Translate "user-speak" into actionable technical requirements for the product and engineering teams.
• Documentation: Maintain a robust internal knowledge base regarding system architecture and common technical workarounds.

Technical Profile

• Code Literacy: Proficiency in at least one major language (e.g., C, Go, or Java) with the ability to navigate large, unfamiliar codebases.
• Systems Thinker: Strong understanding of how different components (APIs, databases, and front-end) interact.
• SQL Mastery: Ability to write complex queries to extract data and diagnose state-related issues.
• Optimization Mindset: An interest in performance—you don't just want it to work; you want it to work efficiently.
• Communication: The ability to explain a "race condition" or a "memory leak" to a non-technical stakeholder without losing them.

Why Join Us?

We value technical curiosity and "under-the-hood" knowledge. You’ll have the autonomy to improve our internal systems and a direct impact on the stability of our product.

We're hiring a Java developer to build ultra-low-latency systems using Aeron and Chronicle.

You will design and optimize high-throughput messaging with Aeron (IPC/UDP, Cluster, Archive), build persistent off-heap data layers with Chronicle Queue and Chronicle Map, and tune JVM performance down to the microsecond.

You bring strong Java (17+), production experience with Aeron or Chronicle Wire & Queue, understanding of mechanical sympathy, lock-free concurrency, off-heap memory, and Linux perf tooling. Trading or market data background preferred.

Bonus: SBE/zero-copy serialization, LMAX Disruptor, kernel bypass (OpenOnload/DPDK), event sourcing, single-writer architectures.

Competitive pay. Hard problems. Microseconds matter.

We're looking for a UI/UX Designer to own the end-to-end experience across our web and mobile platforms. You'll shape how people list, discover, negotiate, and transact — making every interaction feel fast, safe, and satisfying. You'll work closely with product managers, engineers, and our data team to turn user insights into intuitive interfaces.

What You'll Do

• Design user flows, wireframes, and high-fidelity prototypes for listing creation, search and discovery, messaging, checkout, and seller dashboards.
• Conduct user research - interviews, usability tests, and survey analysis - to deeply understand the motivations and pain points of both buyers and sellers.
• Build and maintain a scalable design system that ensures visual consistency across platforms and supports rapid iteration.
• Collaborate with engineers to ensure designs are implemented with precision, providing specs, assets, and guidance through development.
• Use data (conversion funnels, heatmaps, session recordings) to identify friction points and validate design decisions through A/B testing.
• Design trust and safety experiences - rating and review flows, identity verification prompts, dispute resolution interfaces- that make users feel confident transacting with strangers.
• Champion accessibility standards (WCAG 2.1 AA) and inclusive design principles across the product.

What We're Looking For

• 2+ years of product design experience, ideally in a marketplace, e-commerce, or consumer app environment.
• A strong portfolio demonstrating end-to-end product thinking - not just polished visuals, but evidence of problem framing, iteration, and measurable outcomes.
• Proficiency in Figma (components, auto-layout, prototyping) and familiarity with handoff and collaboration tools.
• Experience designing for both iOS and Android, with a solid grasp of platform conventions.
• Comfort with qualitative and quantitative research methods - you can run a usability test and also interpret a funnel chart.
• Strong communication skills - you can articulate design rationale to stakeholders and incorporate feedback without losing sight of the user.

Bonus Points

• Experience with circular economy, sustainability, or peer-to-peer platforms.
• Familiarity with motion design or micro-interactions (Lottie, Rive, or similar).
• Background in illustration or brand design.
• You've designed complex trust, safety, or payment flows before.

What We Offer

• Competitive salary and equity participation.
• Flexible, remote-first work culture with optional co-working stipend.
• Annual learning budget for courses, conferences, and tools.
• A mission-driven team that genuinely cares about reducing waste and making reuse easy.
• The opportunity to shape a product used by millions of people every day.

We're looking for an experienced Go Engineer to join our team and help build, scale, and maintain our payment gateway platform. You'll work on high-throughput, low-latency systems that process financial transactions in real time, ensuring reliability, security, and compliance at every layer.

What You'll Do

Design, develop, and maintain core payment processing services in Go. Build and optimize APIs for merchant integration, transaction routing, and settlement workflows. Implement secure communication with card networks, acquiring banks, and alternative payment providers.

 Ensure PCI DSS compliance across services and infrastructure. Improve system observability through structured logging, metrics, and distributed tracing. 

Participate in architecture decisions, code reviews, and incident response. 

Collaborate with product, risk, and compliance teams to ship features that meet regulatory requirements.

What We're Looking For

3+ years of professional experience writing production Go. Strong understanding of concurrency patterns (goroutines, channels, context propagation). 

Experience building and operating microservices in a distributed environment. 

Familiarity with payment industry concepts such as authorization, capture, refunds, chargebacks, and tokenization. 

Solid grasp of relational databases (PostgreSQL preferred) and transactional integrity. 

Experience with message brokers (Kafka, RabbitMQ, or NATS). 

Comfort working with Docker, Kubernetes, and CI/CD pipelines. Understanding of security best practices: encryption at rest and in transit, secret management, and secure coding.

Nice to Have

Prior experience in fintech, payments, or banking. Familiarity with PCI DSS, PSD2, or 3D Secure protocols.

 Experience with gRPC and Protocol Buffers. 

Knowledge of event-driven architectures and CQRS/event sourcing. Contributions to open-source Go projects.

Tech Stack

Go, PostgreSQL, Redis, Kafka, gRPC, Kubernetes, Prometheus, Grafana, Terraform.

What We Offer

Competitive salary and equity participation.

 Flexible remote or hybrid work arrangement.

 Budget for conferences, courses, and certifications. 

Modern engineering culture with a focus on ownership, autonomy, and continuous improvement. 

The opportunity to work on systems that move real money at scale.