Senior Software Engineer (Telco & Comms)

Callsign; Abu Dhabi; On-site; AED 350,000 - 550,000; Full time

Benefits offered by this job

Health insurance

Visa on arrival support

Annual airfare allowance

Maternity/Paternity leave

25 days annual leave

EOSB gratuity

Job summary

Callsign is hiring a senior software engineer to build secure, scalable systems in a fast-paced cloud environment. You will write production-ready Java 17+ code, design microservices, and drive architecture reviews.

You will threat-model features, implement robust authentication/authorization, and ensure reliable deployments on Kubernetes with Docker, Helm, AWS, and CI/CD pipelines. Mentoring teammates and owning on-call responsibilities are expected.

Qualifications

• 8+ years of experience with Java 17+, Spring Boot and Spring Security.
• Designs and operates microservices for client traffic with API versioning and thorough testing.
• Strong relational data modeling and MySQL tuning experience under load.
• Security-conscious design including authentication, authorization, and secrets management in apps.

Responsibilities

• Write production-ready code and understand the deployment pipeline.
• Draft low-level designs for engineers to implement and participate in architecture reviews.
• Threat-model features and design secure data handling from the start.
• Instrument features, participate in on-call rotations, and drive root-cause analysis.
• Identify gaps early and propose fixes with cost/benefit and AI tool usage.
• Mentor engineers, enforce test quality, and participate in interviewing.

Skills

Java 17+

Spring Boot

Spring Security

JVM debugging

Microservices

Tools

Kubernetes

Docker

Helm

AWS

CI/CD

Job description

Russian hacker, Vladimir Leonidovitch Levin, attempted the biggest bank heist the world had ever seen via dial-up internet in 1994, Zia Hayat, Callsign CEO and founder, was hooked - armchair fraud became a real possibility. From this moment, Zia knew he wanted to play a part in stopping the bad guys and securing the internet for all. Founded In 2012, Callsign's mission has been to make Digital Identity simple and secure for everyone and everything. In that time, we've grown to over 200 employees, opened offices in Singapore and Abu Dhabi, been recognised as a WEF Global Innovator and our technology is being used by many of the world's leading financial institutions to keep millions of consumers safe.

But we aren't stopping here. The identity revolution has only just begun, and we are looking to hire the brightest and inquisitive minds to help us make every web, mobile and physical Interaction seamless and secure. If this sounds like you, lets chat.

Key Responsibilities

• Write production-ready code, and know the pipeline and the chart that ship it.
• Write low-level designs another engineer can build from, and represent the team in architecture reviews.
• Threat-model each feature, and design authentication, authorization, and data handling in from the start
• Instrument before release, take a turn on call, and drive faults to a root cause.
• Find technical gaps early, propose each fix with a cost and a benefit, and use AI tooling.
• Mentor engineers, hold the standard on tests and error handling, and interview candidates.

Requirements

• 8+ years with Java 17+, Spring Boot, and Spring Security, debugging JVM and Spring issues from thread dumps, heap dumps, and traces.
• Designs and operates microservices for client traffic, with API versioning and testing across unit, integration, contract, and load.
• Designs for failure and scale: idempotency, retries, circuit breakers, and caching. Diagnoses bottlenecks with data.
• Strong relational data modeling and query design, primarily in MySQL, with schema and index tuning proven under load.
• Treats security as a design input: OWASP Top 10, authentication and authorization, secrets management, and data handling.
• Writes designs other engineers can build from, and reviews peers' designs.
• Deploys and runs services on Kubernetes with Docker, Helm, AWS, and CI/CD, and debugs failed deployments from the chart or pipeline.
• Owns a change from design through on-call, and instruments it so a fault shows before a client reports it

Nice to Have

• Reactive Java in production: Spring WebFlux, Project Reactor, RxJava, or Vert.x.
• MNO and telco integrations: number insight, SIM swap, and other network signals.
• Authentication and authorization standards: OAuth 2.0, JWT, SAML, FIDO, or WebAuthn.
• Has shipped into banking, payments, or another regulated industry, and has faced an audit or client security review.
• Runs services against contractual uptime commitments: SLIs, SLOs, and error budgets.
• Runs Kafka in production, and has diagnosed consumer lag or rebalance issues.
• Manages infrastructure as code with Terraform

Benefits

• Private Premium Health Insurance
• Visa costs including 1 month paid hotel stay on arrival
• Annual Airfare Allowance for the home country
• 3 months full pay maternity leaves & 2 weeks full pay paternity leaves
• 25 days of annual leave + Callsign Bank Holiday (not included in holiday allowance)
• Competitive Salary
• Gratuity as EOSB