Senior SRE / DevOps Engineer (Kubernetes / A2P Messaging) @ Digital New Agency Poland

This environment will suit you if you enjoy building infrastructure from the ground up, solving hard reliability problems and staying close to the systems you operate in production.You’ll build and operate the infrastructure behind a new high-volume messaging platform, taking ownership from the Kubernetes cluster and networking layer through observability, deployment and incident response.The platform processes around 1 million messages every day, supports approximately 175 customers and 120 suppliers, and maintains more than 300 long-lived messaging connections.This is not a typical stateless web environment. The platform runs long-lived TCP sessions that need stable network endpoints and predictable behaviour during deployments, failures and traffic spikes.You’ll help build the platform across two infrastructure sites and stay with it through production readiness, migration, hypercare and steady-state operation.
What are we looking for?

• You have strong hands-on experience operating self-managed infrastructure and production networking, not only managed cloud services.
• You should be comfortable with encrypted and unencrypted tunneling, including technologies such as IPsec, WireGuard, GRE or similar.
• Strong Linux and networking fundamentals. You are comfortable diagnosing problems involving routing, NAT, firewalls, MTU, TLS or packet-level behaviour.
• Practical troubleshooting experience with tools such as tcpdump and production network diagnostics.
• Experience designing monitoring and alerting, not only maintaining dashboards somebody else created. You understand what deserves to wake a human up, and what does not.
• Strong infrastructure-as-code and CI/CD experience for containerised systems.
• Ability to work directly with engineers from external infrastructure and network providers (English)

What will strengthen your candidacy?

• Experience with telecom, carrier, messaging or other environments built around persistent network connections.
• Knowledge of SMPP, SIP, SS7 or similar telecom protocols.
• Experience configuring or troubleshooting IPsec connectivity with external parties.
• Experience designing or operating multi-site active-active or active-passive environments.
• Hands-on disaster-recovery exercises rather than DR plans that existed only on paper.
• Performance engineering experience, including Linux kernel or network tuning for high connection counts.
• Security hardening experience, including CIS-style benchmarks, vulnerability management or software supply-chain practices.
• Experience being the first SRE or Platform Engineer on a system and defining how it should be operated.

This environment will suit you if you enjoy building infrastructure from the ground up, solving hard reliability problems and staying close to the systems you operate in production.You’ll build and operate the infrastructure behind a new high-volume messaging platform, taking ownership from the Kubernetes cluster and networking layer through observability, deployment and incident response.The platform processes around 1 million messages every day, supports approximately 175 customers and 120 suppliers, and maintains more than 300 long-lived messaging connections.This is not a typical stateless web environment. The platform runs long-lived TCP sessions that need stable network endpoints and predictable behaviour during deployments, failures and traffic spikes.You’ll help build the platform across two infrastructure sites and stay with it through production readiness, migration, hypercare and steady-state operation. ,(Use AI-assisted engineering where it improves delivery - including infrastructure tooling, automation, documentation and runbooks., Build and operate Kubernetes infrastructure across two sites using infrastructure-as-code and automated delivery., Design deployment mechanisms that allow long-lived connections to drain gracefully instead of being dropped during releases., Take ownership of platform networking, including stable ingress and egress IPs, Layer 4 load balancing, TLS and connectivity coordinated with an external infrastructure provider., Build and operate the observability stack: metrics, logs, dashboards and alerting that provide useful signal rather than noise., Design monitoring around real production behaviour, including visibility into individual connections and failure modes., Own certificate lifecycle, secrets management and platform access control., Operate PostgreSQL in a highly available environment, including replication, failover, backups and verified restores., Design and exercise backup and disaster-recovery procedures across two sites., Work closely with engineers and QA on performance and production-scale load testing, investigating what fails first and why., Support the platform during migration and production cutovers., Take part in production incident response and from the steady-state phase, a 24×7 on-call rotation.) Requirements: Linux, IPsec, WireGuard, GRE , CI/CD, SMPP, SIP, SS7