This Django + Celery bug has silently corrupted data in more production apps than you think. And most engineers don't even know they're hitting it. Here's the scenario. User registers. You fire a Celery task to send a welcome email. task = send_welcome_email.delay(user.pk) Looks fine. Works in dev. Works in staging. Then in production — random users never get their email. No errors. No exceptions. Task succeeds. Email just... doesn't send. The bug? Your Celery task ran before Django committed the transaction to the database. The task woke up, queried User.objects.get(pk=user.pk) — and the user didn't exist yet. This is the classic Django + Celery race condition. It's been silently wrecking production apps for years. The old fix was ugly: transaction.on_commit(lambda: send_welcome_email.delay(user.pk)) It worked. But it was boilerplate you had to remember everywhere. Celery 5.4 shipped a proper fix — .delay_on_commit(): send_welcome_email.delay_on_commit(user.pk) One method. Zero boilerplate. Task only fires after the DB transaction commits. Race condition gone. I hit this on a large-scale project handling thousands of user signups. Switched every task trigger to .delay_on_commit() and the ghost failures disappeared overnight. If you're using Celery with Django and still calling .delay() directly in views — check your logs. You might be losing tasks you don't know about. Drop a comment if this has burned you before. I know I'm not the only one. 👇 #Django #Celery #Python #BackendEngineering #DjangoTips #WebDevelopment #BuildingInPublic #SoftwareEngineering
Django Celery Bug Silently Corrupts Production Data
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🎭 #The_"#Translator_Who_Tries_Too_Hard": #Understanding #SerializerMethodField: Ever built a Django API and realized your database model is a bit… boring? You have a first_name and a last_name, but your frontend developer is begging for a full_name or a is_vibe_check_passed field that doesn't actually exist in your SQL table. Enter the SerializerMethodField. In the world of Django Rest Framework (DRF), this field is like that one friend who refuses to just repeat what they heard and instead adds their own "flavour" to the story. 🛠️ How it Works When you define a field as a SerializerMethodField(), you are telling Django: "Hey, don't look for this in the database. I’m going to write a custom function to calculate this on the fly." 👨🍳 The Recipe Define the field: Add it to your serializer class. The "Get" Magic: Create a method named get_<field_name>. The Logic: Do your math, string concatenation, or soul-searching inside that method. Python class UserSerializer(serializers.ModelSerializer): days_since_joined = serializers.SerializerMethodField() class Meta: model = User fields = ['username', 'days_since_joined'] def get_days_since_joined(self, obj): # 'obj' is the actual model instance return (timezone.now() - obj.date_joined).days ⚠️ The Catch (Read: Why your Senior Dev is frowning) While powerful, SerializerMethodField is read-only. You can't POST data back to it. Also, if you use it to run heavy database queries for every single item in a list of 1,000 objects, your API performance will disappear faster than free pizza in a tech office. 🍕💨 TL;DR: Use it when you need to transform raw data into something useful for the frontend, but use it sparingly to keep those response times snappy! 🚀 #Django #Python #WebDevelopment #DRF #BackendTips #CodingHumor
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FastAPI vs Django: Which Wins in 2026? The best framework isn’t the one with the most features—it’s the one that solves your specific bottleneck. If you’re choosing for your next project, here’s a breakdown: Why the industry is shifting to FastAPI - Performance: Built on Starlette and Pydantic, it’s one of the fastest Python - - frameworks. Ideal for high-concurrency or I/O-bound tasks. - Developer velocity: Automatic OpenAPI (Swagger) docs and Python type hints reduce time spent on documentation. - Modern stack: Designed for microservices, AI/ML deployments, and modern frontends like React or Next.js. Why Django isn’t going anywhere - Batteries included: Comes with admin panel, authentication, and ORM out of the box. - Security: Built-in protection against common web vulnerabilities. - Stability: Strong structure for large-scale monoliths and enterprise applications. The verdict Use FastAPI if you want a high-performance engine for modern APIs or microservices. Use Django if you need a fully equipped framework for complex, data-heavy applications. Which side are you on? Are we moving toward a “FastAPI-first” world, or does Django’s ecosystem still reign supreme? #Python #WebDevelopment #FastAPI #Django #SoftwareEngineering #Backend #CodingTips
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Moving from the flexibility of Flask to the "Batteries-Included" power of Django! 🐍🔥 After spending significant time building with Flask, where I enjoyed the "build-it-from-scratch" approach, I decided to dive deep into Django today to see how it handles large-scale architectures. The transition is eye-opening! Here’s what I learned today while building a User Management System: ✅ The Architecture Shift: In Flask, I was used to manual setups for everything. Django’s "Batteries-Included" philosophy (like the built-in User model and Admin panel) is a massive time-saver for rapid development. ✅ From SQL/Manual JSON to Django ORM: I moved away from manual dictionary mapping to using Django’s ORM for JsonResponse. It’s interesting to see how User.objects.all() simplifies data retrieval. ✅ API-First Thinking: I bridged the gap between Backend and Frontend using the Fetch API. Instead of standard page redirects, I built a system where my Django backend serves JSON, and JavaScript handles the UI dynamically via Popups (Modals). ✅ The "Nickname" Logic: One thing I loved? Django’s URL names. In Flask, I’d often hardcode paths, but in Django, using name='user_list_link' makes the code so much more maintainable. The Verdict: Flask taught me how things work under the hood. Django is now showing me how to scale those concepts efficiently. #Python #Django #Flask #WebDevelopment #Backend #CodingJourney #SoftwareEngineering #LearningInPublic #SaaS
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I once spent three days trying to optimize a high-concurrency data pipeline in Django, only to realize I was fighting the framework’s architecture, not the problem. Last week, on a client project involving real-time sensor data, we hit a wall where Django’s ORM and sync nature couldn't keep up with the throughput requirements. The lesson? Pick your Python weapon based on the job, not just what you know best. Django is unbeatable for complex admin panels, strict schema management, and rapid prototyping. It gives you the "batteries included" safety net that lets you ship features instead of building boilerplate. FastAPI, on the other hand, is for when you need to squeeze out every drop of performance. Its asynchronous nature is a massive win for I/O-bound tasks and heavy WebSocket integration. If you’re building a CRUD-heavy enterprise dashboard, stick with Django. If you’re building a high-scale microservice that needs to handle thousands of concurrent requests, move to FastAPI. Don't force a monolith into a microservice’s shoes. What’s the one project where you swapped backends midway because the first choice didn't scale? #Python #SoftwareEngineering #Django #FastAPI #SystemDesign
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Is the "Boilerplate" argument against Django Ninja finally dead? 🐍🥷 I’ve been diving deep into the DRF vs. Django Ninja debate lately. For years, the community pointed to a specific deal-breaker: Boilerplate. I recently revisited a famous 2024 article from Loopwerk that essentially "killed" Ninja for four reasons: 1️⃣ Lack of ViewSets: Writing 30+ lines for basic CRUD that DRF does in 4. 2️⃣ Scattered Logic: Permissions and filters weren't centralized. 3️⃣ Messy Nested Resources: Handling child models (like Characters in a Campaign) was a manual nightmare. 4️⃣ Manual Error Handling: Constantly writing get_object_or_404. But here’s the thing: It’s 2026, and that article is now a history lesson, not a roadmap. With the maturity of Django Ninja Extra and Ninja CRUD, almost all those "weak points" are solved. You now get: ✅ Class-Based Controllers that centralize permissions. ✅ ModelViewSets that handle CRUD in the same 4 lines of code. ✅ Global Exception Handlers that catch 404s and validation errors automatically. The Reality Check: We get the speed of FastAPI/Pydantic, the power of the Django ORM, and the DX of DRF ViewSets—all in one stack. So my question to the backend community: If the "boilerplate" gap is gone, and the performance gap is huge (Pydantic is significantly faster than DRF serializers), why isn't Ninja the absolute default yet? Is it just "Enterprise Inertia," or is there still a secret sauce in DRF that we’re missing? 🧐 #Django #Python #BackendDevelopment #DjangoNinja #WebDev #APIDevelopment
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Your Django app works perfectly. Until it doesn’t. At ~1,000 users, things start breaking: 💥 Slow APIs 💥 Database spikes 💥 Unpredictable lag And the worst part? You don’t even see the problem. --- 🚨 It’s the N+1 Query Problem One of the most common — and most ignored — performance killers in Django. Here’s what happens: You fetch 100 posts → 1 query Then access post.author → +100 queries Total: 101 queries instead of 2 --- It looks like clean code. But behind the scenes? Your database is getting hammered. --- The fix is simple (but most devs miss it): ✔ select_related() for ForeignKey ✔ prefetch_related() for ManyToMany --- 💡 Pro tip: Use django-debug-toolbar Track your queries BEFORE deploying --- Most developers discover this in production. Now you won’t. 🔥 Follow for real backend scaling tips #Django #Python #BackendDevelopment #WebPerformance #SoftwareEngineering
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I just published my first article on "The Django Habits That Hurt You in Go". Coming from Python/Django, a lot of patterns feel natural, with Celery, background jobs, fire and forget tasks, safe retries and queues still feels like "Django". Then you switch to Go after hearing so much about how awesome goroutines are, and naturally, you try to use them like Celery :) Goroutines feel lightweight and easy, so it is tempting to treat them like background workers. But they lack persistence, retry mechanism, fault isolation, and guarantees. This article breaks down: - why goroutines are not a replacement for Celery - the common mistake Django engineers make in Go - what the correct pattern looks like - and what to use instead when you actually need a task queue If you are a Django developer who is giving Go a shot, this will save you from a few painful lessons. https://lnkd.in/ef5BPMYC
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Moving from Django to NestJS, I ran into something that confused me at first — route conflicts 🤯 Django never had this problem. Turns out, that's not an accident. 🤔 I wrote a short breakdown of how NestJS, Django, Flask, and FastAPI each handle the classic `/users/:id` vs `/users/me` conflict — and what it reveals about their routing design. 🛣️ https://lnkd.in/ddBSzrxh #NestJS #Django #Backend #WebDevelopment #Python #TypeScript
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Flask vs FastAPI: A Comprehensive Performance Comparison - As experienced web developers and software engineers, we constantly seek the most efficient tools for our projects. When it comes to Python web frameworks for API development, Flask and FastAPI are two prominent contenders, each offering distinct advantages. This comprehensive comparison article dives deep into their core differences, exploring their respective features, syntax, and real-world performance benchmarks. We will analyze how each framework handles API requests, contrasting Flask's lightweight, unopinionated design with FastAPI's modern, high-performance approach built on asynchronous capabilities and Pydantic for data validation. Our discussion will extend beyond theoretical benchmarks, offering practical tips for implementation and delving into specific real-world examples where Flask's simplicity and vast ecosystem might be preferable, versus scenarios where FastAPI's speed, automatic documentation, and robust type checking provide an undeniable edge. We aim to provide a detailed Flask and FastAPI comparison that helps you understand their performance differences and make an informed decision when choosing between Flask and FastAPI for API development, ensuring your projects are built on the most suitable foundation for scalability and maintainability. Read the full article > https://lnkd.in/gQCc3m5R #iPixelInsights #WebDesignTips #DigitalMarketingStrategy #FrontendDevTalks #UIUXDesign #GoogleAdsHelp #TechForCreatives #SEOForBusiness #DesignVsDev #MarketingTechExplained
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bulk_create and bulk_update don't behave like regular Django saves. Most developers find out the hard way or never realise it! The assumption - they're just faster versions of calling .save() in a loop. Same behaviour, better performance. save() on a single instance does several things - 1. runs pre_save and post_save signals 2. calls full_clean() for validation, handles auto-generated fields 3. returns the saved instance with its new primary key bulk_create and bulk_update bypass all of it. No signals. No validation. No per-instance hooks. Django hands a list of objects directly to the database and walks away. bulk_create - the PK problem ~ By default, bulk_create returns instances without primary keys populated(in Python object) - unless update_conflicts or returning_fields is explicitly set. ~ ignore_conflicts=True silently swallows insert failures - no exception, no log, no signal. A uniqueness violation disappears without a trace. bulk_update - what it can't do ~ bulk_update requires an explicit list of fields. Miss a field - it doesn't update. ~ It cannot update fields using expressions - no F(), no computed values. ~ And like bulk_create - no post_save signals fire. Anything listening for model changes never knows. The performance gain is real - 1000 inserts in one query vs 1000 round trips. But the tradeoffs are real too. Takeaway — -> bulk_create / bulk_update - no signals, no validation, no per-instance hooks -> bulk_create → PKs not populated in Python object by default on PostgreSQL, not at all on MySQL -> ignore_conflicts=True → silent failure, uniqueness violations disappear without exception -> bulk_update → explicit fields only, no F() expressions, missed fields silently skip Have you been bitten by missing signals after a bulk operation? How did you handle downstream consistency? #Python #Django #BackendDevelopment #SoftwareEngineering
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