أنا كريم علي حسين، مهندس برمجيات أول من الإسماعيلية في مصر. أبني وآمِل خدمات خلفية وقابلة للتوسع باستخدام جافا ولارافيل وما يتصل بها من أنظمة آمنة ومتينة.

KA

Karim Ali Hussein.

Staff Software engineer with 8+ years building production systems in SaaS, fintech, and security.

I design backends for multi-tenant products, partner integrations, and high-volume transaction flows—built for real traffic.

I focus on reliable, operable systems: clear service boundaries, data that moves cleanly between services, and end-to-end ownership from architecture through production stability.

Experience

Quantum Security Systems Inc.

Technical Team Lead
Active
Riyadh, Saudi ArabiaOnsiteFeb 2025 — Present
Split a monolithic SOC platform into Spring Boot services so we could ship and fail smaller.
Kept Dev, Staging, and Production environments honest—releases had a real path before prod.
Owned partner-facing APIs with government, fintech, and security vendors—errors, contracts, and on-call behavior included.
Designed event-driven plumbing between services (Kafka and related patterns) so teams weren’t hand-wiring one-off data hops.
Shipped an Outlook phishing reporter: one click turns mail into a structured SOC case.
Helped the org reach ISO/IEC 27001—engineering practice, architecture evidence, and controls that matched how we actually built.
Owned incident storage and search at analyst scale; added observability (New Relic, metrics, logs) so we saw pain before users filed tickets.
Set review norms and internal docs for services and integrations; led cross-functional delivery across backend, frontend, DevOps, QA, and mobile.
Java (Spring Boot)KeycloakKafkaRabbitMQDockerKubernetesGCPGitLab CI/CDJenkinsELKPrometheusGrafanaNew RelicSIEM (Splunk / ELK)Threat Intelligence (MISP, OpenCTI)OWASPISO/IEC 27001RedisPostgreSQL

WalaPlus

Senior Software Engineer
Riyadh, Saudi ArabiaHybridDec 2023 — Feb 2025

The String

Staff Software Engineer
Riyadh, Saudi ArabiaRemoteJan 2022 — Dec 2023

Global Directions

Staff Software Engineer
Ismailia, EgyptOnsiteJan 2021 — Dec 2022

East Direction

Junior Software Engineer
Remote, Saudi ArabiaRemoteJan 2018 — Oct 2020
Focus

What I build

I design and build robust, scalable systems that solve real-world problems.

✦

Multi-tenant SaaS platforms and internal tooling

Fintech-style integrations and secure redemption flows

Cybersecurity systems adjacent to SOC operations

High-concurrency APIs and service-oriented backends

Distributed and event-driven architectures

Stack

Tools & Technologies

A curated set of technologies and tools I use to design, build, and operate reliable, scalable systems.

Languages

The core languages I use to build robust and efficient applications.

JavaJava
PHPPHP
GoGo
TypeScriptTypeScript
PythonPython

Frameworks & APIs

Frameworks and API tools for building modern, scalable services.

Spring BootSpring Boot
LaravelLaravel
SymfonySymfony
FastAPIFastAPI
NestJSNestJS

Data & Messaging

Databases, streaming, and messaging for reliable data flow.

KafkaKafka
RabbitMQRabbitMQ
RedisRedis
MySQLMySQL
PostgreSQLPostgreSQL
MongoDBMongoDB
ElasticsearchElasticsearch
SplunkSplunk

Cloud & Delivery

Platforms and tools for build, deploy, and infrastructure automation.

DockerDocker
KubernetesKubernetes
AWSAWS
GCPGCP
AWS LambdaAWS Lambda
GitLabGitLab
JenkinsJenkins
LinuxLinux
GitGit

Observability

Monitoring, logging, tracing, and alerting for production-grade systems.

ElasticsearchElasticsearch
LogstashLogstash
KibanaKibana
PrometheusPrometheus
GrafanaGrafana
New RelicNew Relic
OpenTelemetryOpenTelemetry
JaegerJaeger
Alerting
Distributed Tracing

Security

Security architecture, identity management, and system hardening practices.

KeycloakKeycloak
OAuth 2.0OAuth 2.0
OpenID ConnectOpenID Connect
JWTJWT
OWASPOWASP
CloudflareCloudflare
ISO 27001
MITRE ATT&CK
SIEM

Architecture

Architectural patterns and principles I follow in system design.

MicroservicesDecompose a system into small, deployable services owned and scaled independently around business boundaries.Event-drivenComponents react to events and messages for loose coupling, resilience, and async workflows.Multi-tenantOne application stack serves many isolated tenants with clear data and auth boundaries.TDDWrite tests that describe behavior first, then implement code until they pass and stay green.System DesignMap requirements to scalable, reliable topologies, tradeoffs, and failure modes before coding.SOAExpose business capabilities as reusable, contract-first services with clear ownership.API GatewayA single entry for routing, auth, rate limits, and observability to many upstream services.REST APIsResource-oriented HTTP interfaces that are stateless, cacheable, and easy to version.CQRSSeparates read and write models and paths to scale, optimize, and evolve each side differently.CDCStream database changes to other systems in near real time for sync, search, and analytics.DDDModel the problem domain in code with a shared language and bounded contexts.Auto ScalingAdd or remove capacity automatically from load, queues, or schedules to match demand.Load BalancingSpread traffic healthily across instances with sticky sessions and failover when needed.High AvailabilityDesign for redundancy, failover, and recovery so the service stays within an SLO under faults.Backup and RecoveryRegular backups, tested restores, and RPO/RTO that match how critical the data is.WebhooksHTTP callbacks to notify other systems the moment an event happens in your service.

Integrations

Third-party platforms, APIs, and external systems I’ve integrated at scale.

Meta (Facebook/Instagram)Meta (Facebook/Instagram)
WhatsApp Business APIWhatsApp Business API
TikTok Ads APITikTok Ads API
Snapchat Marketing APISnapchat Marketing API
OpenAI APIOpenAI API
StripeStripe
PayPalPayPal
Apple PayApple Pay
Microsoft 365 / OutlookMicrosoft 365 / Outlook
iOS IntegrationsiOS Integrations
DocuSignDocuSign

Need technical help or guidance?

If you're a junior, mid-level, or senior engineer and need technical help, guidance, or a second opinion — feel free to reach out. I enjoy helping engineers grow.

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