Senior Backend Engineer (Python/Kotlin)

Zepz; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Unlimited annual leave

Healthcare benefits

Employee discounts

London office access

Job summary

Zepz is hiring a Senior Backend Engineer to join the RemittancePlus team. You will develop and operate the Universal Wallet backend, spanning fiat and crypto flows, with cross-functional collaboration and on-call responsibility.

You will work in a hybrid setup with a global, mission-driven team delivering high-performance money movement services. You will write readable, well-tested code in Python and Kotlin/Java (Spring Boot), influence architecture, and drive reliability across production

Qualifications

• 5+ years of backend experience at scale.
• Proficiency in Python and Kotlin/Java (Spring Boot).
• Experience designing REST/gRPC APIs and relational databases (PostgreSQL).
• Ability to work with AI in a safe, structured environment.
• Familiarity with monitoring tools like Grafana and Loki.
• Knowledge of Kubernetes, ArgoCD, AWS, and Terraform is advantageous.

Responsibilities

• Develop and operate the Universal Wallet backend services at scale.
• Collaborate with cross-functional teams to deliver features end-to-end.
• Take part in on-call rotation and production support to drive remediation.
• Review design and code to improve architecture and reliability.
• Improve monitoring and observability of services across environments.

Skills

Backend engineering

Python

Kotlin/Java

REST/gRPC APIs

PostgreSQL

AI safety

Grafana/Loki

Kubernetes

AWS

Terraform

Tools

Grafana

Loki

ArgoCD

Spring Boot

AWS

Terraform

Job description

Job Description

Join Zepz: Breaking Down Borders, Together

Our Meaningful Mission

At Zepz, we're all about breaking down barriers for our customers and our teammates. Our purpose is deeply personal — we provide a lifeline and deliver opportunities to cross-border communities that need it most through cutting edge finance and tech. Zepz is the power behind WorldRemit and Sendwave, driven by the mission to celebrate the incredible impact migrants have, both at home and abroad. We're not just moving money; we're building a world that truly recognizes and supports global connections.

Who You'll Be Joining

We look for mission-driven builders who thrive in a fast-paced environment connected to a true purpose. We're an always-developing team of experts that enjoy problem solving and bring clarity to tough challenges. At Zepz, we are Relentless Learners, always seeking feedback, and Responsible Owners, treating company resources like your own. We depend on Transparent Communicators who keep the team aligned through open, honest talk — this matters even more on a fully remote team, where clear written updates carry the weight that hallway conversations would elsewhere.

Our Core Commitments — What We Live By

• Integrity: We always do the right thing. It's simple, but it's the foundation of everything we build for our customers and each other.


• Outcomes: We work for our customers. Their success and prosperity are the results we focus on delivering.


• Velocity: We are fast! We maintain high energy levels and make smart decisions quickly, keeping us nimble and ahead of the curve.

Perks of Joining Our Team

We believe in empowering colleagues because we genuinely trust our team. Our culture is founded on this high trust, which naturally encourages the high ownership that drives us to meet our shared high expectations and deliver high performance. While we have all the tools to work remotely, we value the purpose and benefits of in-person connections so we expect our teams to come to the office on a regular basis, and therefore be within a comfortable commutable distance from our London office. Alongside a great office environment, think unlimited annual leave, great healthcare benefits, and employee discounts. We want you to thrive and focus entirely on making your biggest impact! In turn, we expect you to bring high ownership and commitment to your work. This is a place where we value trust and high performance, and we'll provide the environment and support needed for you to excel.

About the Role

At Zepz, our engineers are passionate about delivering a solid customer experience and are eager to contribute to the product, regardless of their tech stack. We are seeking engaged and customer-focused engineers who are committed to writing quality code and dedicated to their contributions at Zepz.

As a Senior Backend Engineer on RemittancePlus, you'll work within a cross-functional feature team building and operating Universal Wallet — the multi-currency, crypto-capable wallet powering deposits, withdrawals, and balances for millions of customers across Sendwave. This spans fiat and stablecoin flows, on/off-ramp integrations, and settlement — high-traffic, money-movement systems where correctness and reliability directly determine whether a customer's funds move when and where they expect.

You will have the autonomy to make platform decisions and provide insights to the rest of the team. You'll collaborate closely with engineers of varying experience levels and interests, helping to improve our services, build pipeline, and tooling across a mixed stack — Python services in sw-backend, and Kotlin/Java services underpinning Universal Wallet. You'll be committing, reviewing, and shipping code early on, with the support and time to ramp up properly — there's a lot to learn across our diverse systems.

Reliability is core to the role: the team owns its services in production, and you'll take part in the on-call rotation — responding to incidents, supporting production, and driving remediation and long-term fixes.

What You Bring to the Table

Technical Skills

• 5 years of experience building backend services at scale.


• Strong proficiency in Python and Kotlin/Java (Spring Boot) is expected, as Universal Wallet spans both stacks.


• Experience designing and operating REST/gRPC APIs, event-driven systems, and relational databases (e.g., PostgreSQL).


• Ability to work with AI in a safe, structured environment.


• Ability to work with tools like Grafana and Loki for debugging and fault-finding.


• Some understanding of Kubernetes, ArgoCD, and AWS cloud is advantageous, as well as technologies like Terraform.

Technical Execution

• You take pride in writing readable, well-designed, and well-tested software.


• You will improve code structure and have an impact on architecture.


• You will actively review tech designs and code from others.


• You'll improve monitoring and the health of your team's systems.


• You'll participate in on-call and production support — triaging incidents, restoring service, and following through on remediation so issues don't recur.

Collaboration & Async Communication

• You write clear, self-contained updates (Slack, Jira, PRs, design docs) that don't require a live conversation to understand.


• You default to documenting decisions and context rather than relying on verbal handoffs.


• You build relationships with other engineering teams and identify collaboration opportunities, even without in-person contact.


• You own larger pieces of work, assist with design and technical/implementation choices, and influence the roadmap within your team.


• You communicate easily with non-technical team members and can translate their feedback into code.


• You adjust quickly and effectively to shifting priorities and complexity.

Customer Obsession

• Care about users, and want to give them an improved, simpler experience.


• Are more of a \"get it done\" than a \"perfectionist\" type person — you value getting features into the hands of our users.


• Aren't afraid to throw away code you wrote — because after testing, a flow you built doesn't work as well as a different one.

Bonus Points If You Have

• Experience with Rust, particularly for Solana or other blockchain/crypto integrations — a strong plus given Universal Wallet's stablecoin and on-chain settlement work.


• Experience with wallet, ledger, or payment systems (balances, reconciliation, settlement).


• Familiarity with KYC/AML regulatory requirements in international payments.


• Experience in fintech or other regulated, high-availability environments.


• Familiarity with any of the communities we serve.

AI Literacy & Tools

As Zepz continues to build AI into how we work, we expect everyone to engage with it as a core part of their role. For this position we are looking for:

• A genuine curiosity about AI and how it can be applied in your area of work, from accelerating analysis and insight generation, to improving how we design and deliver processes and communications.


• Practical experience using AI tools in a professional context, whether to connect information, draft content, build frameworks, or create insights from data. We want people who actively use AI to increase productivity, not those who are waiting to be told to.


• Strong AI literacy. An understanding of what AI assistants can and cannot do, how to prompt effectively, and how to critically evaluate AI-generated output before using it.


• Awareness of the ethical considerations and responsible use of AI in the workplace, particularly in the context of sensitive data, customer experience, and compliance.


• Prior experience using Claude (Anthropic) is a nice-to-have but not essential — what matters most is that you are genuinely engaged with AI as a tool, comfortable experimenting, and eager to share what works with your wider team.

If you want to join us in our journey to help break barriers in financial access and improve lives globally, there's no better place or time to join.

Our global team of 800+ people is spread across six continents. We aspire to hire the best mix of people from former Olympians to YouTube influencers and we speak over twenty languages. This incredible diversity isn't a bonus; it's the engine that lets us serve the world.