Java Backend Developer with Kotlin

Net2Source (N2S); Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

Net2Source Inc. in London is seeking a Java Backend Developer with Kotlin for a Hybrid role. The position emphasizes deep technical craft alongside capital markets domain knowledge, with 3 days onsite weekly.

You will own end-to-end delivery, practice test-driven development, and build event-driven systems in a fast-growing organisation. Applicants should bring strong Java/Kotlin background, JVM stack experience, and familiarity with Kafka, SQL Server, NoSQL stores, and observability tools.

Qualifications

• Hands-on Java and Kotlin development in production systems.
• Strong TDD practices with end-to-end ownership.
• Experience with JVM stack and messaging systems.
• Exposure to capital markets trading or post-trade environments.
• Familiarity with data stores (SQL/MongoDB) and cloud object storage.

Responsibilities

• Build scalable backend services in a capital markets context.
• Own design and quality through TDD and CI/CD.
• Collaborate in an Agile, iterative environment with frequent releases.
• Design event-driven architectures with proper replay semantics.

Skills

Java

Kotlin

TDD

Event-driven

CI/CD

Agile

Tools

Kafka

Solace

TIBCO EMS

SQL Server

MongoDB

S3 object store

OpenTelemetry

ELK stack

Grafana

HashiCorp Vault

CyberArk

Job description

Net2Source Inc. is one of the fastest growing diversities certified global workforce solutions companies with an unprecedented YoY growth of over 100% for last 6 years working with Fortune 1000/Global 2000 across 34 countries and 5 continents including North America, South America, Europe, Asia, Australia, and Middle East.

About the Role:

Job Title – Java Backend Developer with Kotlin

Location – London, UK

Mode of Work – Hybrid (3 Days Onsite Per Week)

Type of Hiring – Permanent / Fixed Term Employment (FTE – 12+ Months)

Technical Experience:

Experience in any of the following strengthens a candidate’s profile None are individually mandatory beyond Java and TDD

• JVM Kotlin
• Messaging Kafka Solace TIBCO EMS
• Data SQL Server MongoDB S3 object store
• Observability Open Telemetry ELK stack Grafana
• Secrets Management Hashi Corp Vault CyberArk

Domain Experience:

• Candidates must have hands‑on experience working in or alongside a capital markets trading or post trade environment
• Crucially we seek engineers who are proactive in developing deep domain knowledge themselves rather than solely relying on Business Analysts for this expertise
• The following are indicators of the required depth not an exhaustive list
• In‑depth understanding of the trade lifecycle including Trade Booking and Position Management principles
• Practical experience with post trade operations such as Cashflow Calculation Settlement Wires Client Reporting and Accounting principles
• Familiarity with corporate actions regulatory reporting and integrating with risk valuation systems in an equities context
• Understanding of Prime Brokerage Synthetic Swap or Cash Equity operational flows is a significant advantage
• Exposure to regulatory reporting obligations in a financial context e.g., 871m EMIR MiFID is advantageous
• Candidates should be able to demonstrate this experience at interview with concrete examples not high-level familiarity

Requirement:

• We are looking for engineers who combine deep technical craft with genuine capital markets domain knowledge The two are equally important candidates who have one without the other are unlikely to be effective in this environment
• Test‑driven Development is non‑negotiable Engineers must be practitioners of TDD not just advocates and are expected to own the quality of their deliverables end‑to‑end rather than outsourcing it to a separate QA group We expect candidates to demonstrate this through their approach to design not just their ability to write tests after the fact This will be assessed at interview
• Event driven architecture practical experience designing and building systems on message passing and event sourcing patterns including failure handling ordering guarantees and replay semantics
• Agile delivery strong preference for engineers who have worked in genuine iterative delivery environments with short feedback loops not waterfall projects labelled as agile This includes a focus on Continuous Integration Delivery using techniques such as trunk‑based development and achieving frequent 1 per week production releases during regular business hours without any service interruption