DEV Community: Ricardo Campos

Mailgun API returning 401

Ricardo Campos — Sun, 22 Jun 2025 20:01:43 +0000

How to solve 401 error on Mailgun API request

I've been fighting this error for over one hour, and the solution is quite simple.

Disclaimer: This solution is for a Spring Boot API, but might help you on different languages.

The reason I'm creating this post, even in AI times, is that Claude wasn't able to point me clearly the issue, so, here it goes:

When authenticating your API request programmatically, make sure you add a simple Authorization header instead of a BasicAuth header directly.

Do this:

headers.set(HttpHeaders.AUTHORIZATION, basicAuth("api", appConfig.getMailgunApiKey()));

And don't do this:

headers.setBasicAuth(basicAuth("api", appConfig.getMailgunApiKey()));

For reference, in case you're wondering:

private String basicAuth(String username, String password) {
  String auth = username + ":" + password;
  return "Basic " + Base64.getEncoder().encodeToString(auth.getBytes(StandardCharsets.UTF_8));
}

Now if you're still getting 401, I'll leave some items for you to double check:

API Key: double check the API key, if it's being applied and used correctly;
Domain Verification: Although I'm not 100% sure this is a blocker, make sure your domain is verified and all check are green;
Region Mismatch: If you're working within EU region, you might have to se the EU URL: https://api.eu.mailgun.net/v3/... instead of the api.mailgun.net directly.

That's it. Thank you. Follow me for more. I'll be posting small fixes like this more often.

How I organize myself as a tech lead

Ricardo Campos — Sat, 23 Mar 2024 20:19:55 +0000

Hi everybody! Today I want to share how I finally was able to get myself organized as a technical lead working in two teams with different products.

TL;DR

Define what tasks should be finished daily, weekly and monthly;
Create templates with basic models, but helpful;
Daily or weekly work with these templates making changes and adding your actual tasks;
Work with check-boxes and leave unfinished work unchecked;
Always start with unfinished work from yesterday (or the day before)
Don't answer your team's questions right away;
You're done :)

Complete article

If you still here, I assume you'd like to read more. So, here's a quick background for context.

I'm a shared resource between two Agile teams (with Scrum), handling planning, backlog refinement meetings, and all the usual Scrums ceremonies. Also, I'm the Senior developer for both teams, which means they're constantly asking for help. As you can imagine, managing time and tasks can get pretty complex.

Yes, it's complex. And when dealing with complex problems like this, let's break it down and work with small pieces.

First up, define your deliverables! Take a moment to consider everything your company, your team, and your peers expect you to do. What you need to do daily, and weekly. Make a note of it.

Next, work with templates! Templates can get you set quickly in terms of what and how you need to work. I've found Trello to be a good tool, but Todoist, Notion, and probably others work too.

I like Trello because I can have my template card on top of the list and easily create my cards.

Here's mine daily template:

Review team River PRs
Review team Mountains PRs
Focus at least 30 minutes on team River issue 387
Focus at least 30 minutes on team Mountains task 297

And weekly:

Summary tasks report
Review tasks in the backlog that needs more information
Get ahead with slides for the sprint review

Remember, the more organized you are, the easier it gets. I prefer doing things at the same time everyday, if possible. Writing your tasks for the day should be your first activity.

Now, work with check-boxes! Check-boxes can visually indicate when something is done and when it's pending. Plus, checking things off gives our brains a great feeling. I like leaving unfinished work unchecked for that day, rather than carrying it over to the next.

Prioritize yesterday's work! Ideally, we should finish yesterday's work first, so it doesn't get forgotten.

Focus time! This is gold. As a technical leader, people will often ask you things, usually for help. But not all questions are super important. Most of them can wait. People can often find an answer themselves because they need to. You can review later. But use this power wisely.

You're done! Finally, you'll have a better organization for your tasks, your daily work, reports, documentations, everything. The more you do, the better you get. Trust me.

Thank your for reading. I'd love to hear your comment on this.

Happy coding.

Delivering value

Ricardo Campos — Fri, 06 May 2022 17:42:59 +0000

What's up, my friend? What pops into your mind when you think of delivering value?

This is a topic that made me think for a long time and still does today. Mostly because it throws me out of my comfort zone. Often I get myself wondering about the reasons that I do things the way I do.

Let me clarify. As a programmer, I need to carry about code quality, docs, if I'm keeping things simple, if I'm repeating code, if I'm writing in the best way possible, and so on. In general, that's good, however, sometimes, it can be a problem. I need to remember frequently that those details little or nothing will bring value to the final product and to the customer.

Understand that I'm not saying that I should write bad code, I'm just raising this question about sometimes sacrificing time and putting too much effort or more than it should. Don't write bad code. So what I want to do is bring that question: are we delivering value for sure? Or we're just focused on our own meters (from the company sometimes) that just make our lives worse?

Often I see flame war about tech, languages, libs, and hippies frameworks that even though they have good reasons, in most cases, they just want to be hippies. Sorry to say this, but that is what I have seen out there! We don't see people talking about the best way to attend to the customer, about inviting him to decisions and project phases. It seems that the main idea is something like "I don't care about users, here I'm the boss, my code, my way."

I don't want to go deep, just bring that to light.

To finish I want to let the record that today I'm much more customer-oriented than company-oiriented. The goal it's the product, quality, and user experience. And don't just a good source code. I tell you again that a good source code it's crucial, but can't decide the result.

That's it! I'd love to see your comment.

Till next time! <o/

Originally posted at https://ricardocampos.blog/post/delivering-value/ on Oct 24, 2020, 10:43:35 PM

English - Gold tips

Ricardo Campos — Wed, 04 May 2022 18:40:53 +0000

This is the beginning of a series of posts about English learning. I want to highlight some points in the English learning process that can make a huge difference, especially if these things were noticed at the beginning of the process. Besides these tips, I want to give you a list of material, sources where and how you can study. So, let's get started!

Very well. Many of us are used to studying, learning, having access to a book, then learning grammar, starting to apply, and then keep learning. More or less in that same order. And that's right, there's nothing wrong about it. But if we're talking about learning conversation, and fluency, to be precise, this approach just doesn't work.

If you want to learn more grammar, there you go. You can keep your studies like you're probably doing. Get some books accordingly to your level and study them. However, if you're interested in keeping a conversation flow going, this standard method doesn't help at all. And the worse is that this same method is still presented on many many English schools around there.

I'm sorry for complaining! But then, how to get to fluency? The answer is simple, just learn how to speak, and focus on pronounciation. Practice hard words, and hard sounds, and discover how and when to use them. To learn in the same way as babes do, naturally. Listening, repeating, getting wrong, repeating again, and understanding their meaning.

This approach is not new, and it's known as learning backward because you focus on understanding and speaking first than writing and grammar. Maybe that can be new for you, and even shocking. Probably you took the wrong way for so long. The bright side is that now you know how to finally be fluent. If you want to know more about it, I would recommend you this podcast episode See it here, they speak Brazilian Portuguese and English.

And now, here are the tips as promised, where you can find good content and material to really study. Not only theory.

Pronounce

Start exactly where you are. Think of the most difficult word for you right now. Let's say that it's the word mother, focus on it, repeat 10, 20, 50, 100 times. Until you can say it nicely, the closest possible from a native speaker. For a good pronunciation reference, you can use the linguee page, also forvo a website that has pronounces recorded by natives.

Resources

https://forvo.com/
https://www.linguee.com/
Cake app (you repeat and the app shows if you're good or not)
Elsa Speak app (super nice for pronunciation!!)
/TH/ sound: https://www.inglesnuecru.com/370-e-hoje-estamos-falando-sobre-o-som-do-th/
/R/ sound: https://www.inglesnuecru.com/532-o-som-do-r-em-ingles-e-suas-dificuldades/
More /R/ sound: https://www.inglesnuecru.com/586-o-som-do-r-em-ingles-e-como-aprender-de-uma-vez/
The 3 /T/ Sounds: https://www.inglesnuecru.com/585-os-3-ts-do-ingles-e-como-podemos-te-ajudar-a-desvendar/
The /S/ sounds: https://www.inglesnuecru.com/531-silencio-por-favor-silent-s-e-silent-b-em-ingles/
/AW/ sound: https://www.inglesnuecru.com/523-voce-sabe-pronunciar-o-aw-sound-em-ingles/
/AH/ sound: https://www.inglesnuecru.com/522-como-pronunciar-o-ah-sound-em-ingles/
Repetition (shadowing): listening natives speakers and repeat out loud after them without thinking to much. More here: https://www.youtube.com/watch?v=ljEP_ywBm7I

Listening

If you can understand almost everything in an English conversation, you can start with something more real, like the news, or even private classes online. Another great option is to listen to podcasts (I love this, I'm a podcast addict).

Important: pay attention to the pronunciation. Try to understand, yes, but the key is to be able to speak like them. To be able to reproduce the exact same sound.

Resources

English Class 101 on Youtube: https://www.youtube.com/channel/UCeTVoczn9NOZA9blls3YgUg
Inglês Nu e Cru Rádio: https://www.inglesnuecru.com/episodes/
Watch a bunch of movies in English WITHOUT SUBTITLES.
Radio Garden, a web radio station. This one it's from NYC: http://radio.garden/visit/new-york-ny/9Yi25umJ

Conversation

And last but not least, the practice itself! Challenge yourself and make mistakes. Don't skip this part. Try, even if you are not so confident, or have a short vocabulary. Just go for it.

If you don't have a group, or friends, or something like that, I strongly recommend trying TNT, especially if you're Brazillian. You must subscribe for a free account and then you can book meetings. The meetings are on the Zoom platform for one entire hour. They have meetings every weekday, you can choose an hour that works best for you and book. The meeting link will be emailed to you.

Resources

Subscription for TNT: https://www.talkntalk.com.br/

That's it. If you have any question, please, talk to me. I'm seriously interested about knowing you're experiente.

See ya folks!

Originally posted at https://ricardocampos.blog/post/english-gold-tips/ on Jun 21, 2020, 10:43:35 PM

Começando no Inglês

Ricardo Campos — Wed, 09 Mar 2022 16:57:15 +0000

Faala pessoal, tudo bem? Hoje vou passar rapidão só pra deixar umas dicas de como começar a estudar o ~~maldito~~ bendito Inglês. Pega um café e bora!

Primeiro passo

Ter um motivo forte. Mas bem forte. Raiva e/ou ódio por ter perdido uma oportunidade maravilhosa também servem (meu caso kk).

Segundo passo

Agora que você está sangue no zóio, faca na caveira, tem que escolher um assunto que te agrada. Agrada muito. Mas seja específico(a). Pode ser um esporte, um tema de notícias, uma atividade.

Com o assunto na mão, é hora de começar a seguir (Twitter, Instagram, Linkedin, Newsletter, Google News, etc.) e começar uma leitura diária.

Aqui está um segredo: Contato diário.

IMPORTANTE: Dê um jeito de internalizar que o Inglês vai ser parte da sua vida. Por isso deve ser algo que você gosta. Se você não gostar, seu cérebro bloqueia o aprendizado, ou tira o teu foco.

Terceiro passo

Rotina. É isso mesmo meu(minha) amigo(a). ~~Não vou dizer disciplina pra não parecer aqueles coachs chatos hauhau.~~

Encontre um momento (ou vários, até melhor) pra ter esse contato. Importante notar que pode até ser um momento relax, como hora do café, mas não pode ser muito relax, pois o ceu cérebro desativa o modo aprendizado nessa hora.

Quarto passo

Tenha paciência. Vai levar um tempo. Não pense em anos, ou no objetivo final. Pois vai parecer distante demais, inalcancável, e vai te desmotivar.

Faça um poco por dia e confie no processo.

Citando uma frase traduzida de um podcast que gosto muito: Continue a boa luta e saiba perder.

Dicas de rotina

Próximo ao horário do café da manhã (antes ou depois), confira uma notícia ou algum conteúdo rápido.
Em algum horário que for melhor, dedique pelo menos 30 minutos de estudo focado.
Descubra o que funciona pra você. Talvez seja inverter essa ordem aqui em cima. Seja flexível.
Escolha um podcast e tente ouvir com frequência. Vai acelerar seu aprendizado. Aproveite a caminhada, o trajeto pra casa, a academia, etc.

Dicas de podcasts

Inglês Nu e Cru Rádio
- Iniciante
- Sobre ensino de Inglês exclusivo para Brasileiros(as). Com muitas dicas pra nós.
- https://www.inglesnuecru.com/episodes/
Gadget Lab
- Intermediário
- Sobre tecnologia.
- https://open.spotify.com/show/11hUjoJv4FxFnw9r0mHIsC
All Things Considered
- Avançado
- Notícias rápidas
- https://www.npr.org/programs/all-things-considered
All Ears English
- Iniciante
- Dicas de conversação, expressões, bem animado
- https://www.allearsenglish.com/

Dicas de apps

Elsa Speak. Só indico este.

Dicas de canais no YT

English in Brazil by Carina Fragozo - https://www.youtube.com/channel/UCcNm9fM9V5wf-0PZVmkM08g
English with Veronika Mark - https://www.youtube.com/c/VeronikaMark
Learn English with EnglishClass101.com - https://www.youtube.com/c/EnglishClass101

Dicas de onde praticar NA FAIXA

Dicas finais

Não estude mais do que 30 minutos por vez
Esqueça filmes e séries dublados
Na TV ative as legendas em Inglês e preste atenção nos SONS. Os Sons são a chave.
Se tiver tempo, (ou pressa), veja sua(seu) série/filme em Inglês e sem legenda. Preste atenção e tente entender, mesmo que seja pelas imagens e contexto. Depois reassista com a legenda.
Se você gosta de vídeos do TED Talks, eles são uma excelente opção de estudo. Tem transcrição e trandução.

Valeu por ter lido até aqui. Se tiver uma dúvida específica ou recomendação, ou qualquer pergunta mesmo, comenta ai.